Organic semiconducting compounds

ABSTRACT

The invention relates to novel organic semiconducting compounds containing an asymmetrically dihalogenated electron-deficient unit, to methods for their preparation and educts or intermediates used therein, to compositions, polymer blends and formulations containing them, to the use of the compounds, compositions and polymer blends as organic semiconductors in, or for the preparation of, organic electronic (OE) devices, especially organic photovoltaic (OPV) devices, perovskite-based solar cell (PSC) devices, organic photodetectors (OPD), organic field effect transistors (OFET) and organic light emitting diodes (OLED), and to OE, OPV, PSC, OPD, OFET and OLED devices comprising these compounds, compositions or polymer blends.

TECHNICAL FIELD

The invention relates to novel organic semiconducting compoundscontaining an asymmetrically dihalogenated electron-deficient unit, tomethods for their preparation and educts or intermediates used therein,to compositions, polymer blends and formulations containing them, to theuse of the compounds, compositions and polymer blends as organicsemiconductors in, or for the preparation of, organic electronic (OE)devices, especially organic photovoltaic (OPV) devices, perovskite-basedsolar cell (PSC) devices, organic photodetectors (OPD), organic fieldeffect transistors (OFET) and organic light emitting diodes (OLED), andto OE, OPV, PSC, OPD, OFET and OLED devices comprising these compounds,compositions or polymer blends.

BACKGROUND

In recent years, there has been development of organic semiconducting(OSC) materials in order to produce more versatile, lower costelectronic devices. Such materials find application in a wide range ofdevices or apparatus, including organic field effect transistors(OFETs), organic light emitting diodes (OLEDs), organic photodetectors(OPDs), organic photovoltaic (OPV) cells, perovskite-based solar cell(PSC) devices, sensors, memory elements and logic circuits to name justa few. The organic semiconducting materials are typically present in theelectronic device in the form of a thin layer, for example of between 50and 300 nm thickness.

One particular area of importance is organic photovoltaics (OPV).Conjugated polymers have found use in OPVs as they allow devices to bemanufactured by solution-processing techniques such as spin casting, dipcoating or ink jet printing. Solution processing can be carried outcheaper and on a larger scale compared to the evaporative techniquesused to make inorganic thin film devices. Currently, polymer basedphotovoltaic devices are achieving efficiencies above 10%.

Another particular area of importance are OFETs. The performance of OFETdevices is principally based upon the charge carrier mobility of thesemiconducting material and the current on/off ratio, so the idealsemiconductor should have a low conductivity in the off state, combinedwith high charge carrier mobility (>1×10⁻³ cm² V⁻¹ s⁻¹). In addition, itis important that the semiconducting material is stable to oxidationi.e. it has a high ionisation potential, as oxidation leads to reduceddevice performance. Further requirements for the semiconducting materialare good processibility, especially for large-scale production of thinlayers and desired patterns, and high stability, film uniformity andintegrity of the organic semiconductor layer.

Organic photodetectors (OPDs) are a further particular area ofimportance, for which conjugated light-absorbing polymers offer the hopeof allowing efficient devices to be produced by solution-processingtechnologies, such as spin casting, dip coating or ink jet printing, toname a few only.

The photosensitive layer in an OPV or OPD device is usually composed ofat least two materials, a p-type semiconductor, which is typically aconjugated polymer, an oligomer or a defined molecular unit, and ann-type semiconductor, which is typically a fullerene or substitutedfullerene, graphene, a metal oxide, or quantum dots.

However, the OSC materials disclosed in prior art for use in OE deviceshave several drawbacks. They are often difficult to synthesize or purify(fullerenes), and/or do not absorb light strongly in the near IRspectrum >700 nm. In addition, other OSC materials do not often form afavourable morphology and/or donor phase miscibility for use in organicphotovoltaics or organic photodetectors.

Therefore there is still a need for OSC materials for use in OE deviceslike OPVs, PSCs, OPDs and OFETs, which have advantageous properties, inparticular good processability, high solubility in organic solvents,good structural organization and film-forming properties. In addition,the OSC materials should be easy to synthesize, especially by methodssuitable for mass production. For use in OPV cells, the OSC materialsshould especially have a low bandgap, which enables improved lightharvesting by the photoactive layer and can lead to higher cellefficiencies, high stability and long lifetime. For use in OFETs the OSCmaterials should especially have high charge-carrier mobility, highon/off ratio in transistor devices, high oxidative stability and longlifetime.

It was an aim of the present invention to provide new OSC compoundswhich can overcome the drawbacks of the OSCs from prior art, and whichprovide one or more of the above-mentioned advantageous properties,especially easy synthesis by methods suitable for mass production, goodprocessability, high stability, long lifetime in OE devices, goodsolubility in organic solvents, high charge carrier mobility, and a lowbandgap. Another aim of the invention was to extend the pool of OSCmaterials available to the expert. Other aims of the present inventionare immediately evident to the expert from the following detaileddescription.

The inventors of the present invention have found that one or more ofthe above aims can be achieved by providing compounds as disclosed andclaimed hereinafter. These compounds comprise an asymmetricallydihalogenated, electron-deficient benzofused unit as shown in formula I.

It has been found that compounds comprising such a unit, and preferablyfurther comprising an electron donating unit, can be used as OSCs whichshow advantageous properties as described above.

A. Makarov et al., J. Fluor. Chem. 2014, 165, 123-131 disclosesbenzothiadiazole and benzoselenodiazole with fluorine and chlorinesubstituents as building blocks for compounds with potential use inbiomedicine or materials science. However, the compounds as disclosedand claimed hereinafter have hitherto not been disclosed in prior art.

SUMMARY

The invention relates to a compound comprising a unit of formula I

wherein the individual radicals, independently of each other and on eachoccurrence identically or differently, have the following meaningsone of X¹ and X² is F and the other of X¹ and X² is Cl,

-   U NR, O, S, Se or Te,-   R H or linear, branched or cyclic alkyl with 1 to 30, preferably 1    to 20, C atoms, in which one or more CH₂ groups are optionally    replaced by —O—, —S—, —C(═O)—, —C(═S)—, —C(═O)—O—, —O—C(═O)—, —NR⁰—,    —SiR⁰R⁰⁰—, —CF₂—, —CR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— in such a manner    that O and/or S atoms are not linked directly to one another, and in    which one or more H atoms are optionally replaced by F, Cl, Br, I or    CN,-   Y¹, Y²H, F, Cl or CN,-   R⁰, R⁰⁰H or linear or branched alkyl with 1 to 20, preferably 1 to    12, C atoms that is optionally fluorinated,-   X⁰ halogen, preferably F or Cl,    with the proviso that the following compounds are excluded

wherein X¹, X² and U are as defined above, A and B each independentlydenote H or F, or one of A and B denotes F and the other denotes Cl.

The invention further relates to the use of the units of formula I in oras repeating units in conjugated polymers.

The invention further relates to a compound according to the presentinvention which is a conjugated polymer comprising one or more repeatingunits of formula I.

The invention further relates to a compound according to the presentinvention which is a small molecule or oligomer comprising one or moreunits of formula I.

A compound comprising one or more units of formula I is hereinafter alsoreferred to as “compound according to the (present) invention”.

The invention further relates to a compound according to the presentinvention which is a monomer comprising a unit of formula I, optionallyfurther comprising one or more additional arylene or heteroaryleneunits, and further comprising one or more, preferably two reactivegroups on the benzene ring in ortho-position to the groups X¹ and X²,wherein these reactive groups can be reacted to form a small molecule,oligomer or conjugated polymer as described above and below, preferablyin an aryl-aryl coupling reaction.

The invention further relates to a compound according to the presentinvention which is a small molecule or oligomer comprising one or moreunits of formula I and further comprising one or moreelectron-withdrawing groups.

The invention further relates to novel synthesis methods for preparingcompounds according to the present invention, and novel intermediatesused therein.

The invention further relates to the use of compounds according to thepresent invention as semiconductor, either as electron acceptor orn-type semiconductor, or as electron donor or n-type semiconductor,preferably in a semiconducting material, an electronic or optoelectronicdevice, or a component of an electronic or optoelectronic device.

The invention further relates to the use of compounds according to thepresent invention as dyes or pigments.

The invention further relates to a composition comprising one or morecompounds according to the present invention, and further comprising oneor more compounds having one or more of a semiconducting, hole orelectron transport, hole or electron blocking, insulating, binding,electrically conducting, photoconducting, photoactive or light emittingproperty.

The invention further relates to a composition comprising one or morecompounds according to the present invention, and further comprising abinder, preferably an electrically inert binder, very preferably anelectrically inert polymeric binder.

The invention further relates to a composition comprising a compoundaccording to the present invention which is an electron donor or p-typesemiconductor, and further comprising one or more electron acceptors orn-type semiconductors, preferably selected from fullerenes orsubstituted fullerenes, or from non-fullerene acceptors.

The invention further relates to a composition comprising a compoundaccording to the present invention which is an electron acceptor orn-type semiconductor, and further comprising one or more electron donorsor p-type semiconductors, preferably selected from conjugated polymers.

The invention further relates to a composition comprising one or moren-type semiconductors, at least one of which is a compound according tothe present invention, and further comprising one or more p-typesemiconductors.

The invention further relates to a composition comprising one or moren-type semiconductors, at least one of which is a compound according tothe present invention, and at least one other of which is a fullerene orsubstituted fullerene, and further comprising one or more p-typesemiconductors, preferably selected from conjugated polymers.

The invention further relates to a bulk heterojunction (BHJ) formed froma composition comprising a compound according to the present inventionas electron acceptor or n-type semiconductor, and one or more compoundswhich are electron donor or p-type semiconductors, and are preferablyselected from conjugated polymers.

The invention further relates to a bulk heterojunction (BHJ) formed froma composition comprising a compound according to the present inventionas electron donor or p-type semiconductor, and one or more compoundswhich are electron acceptors or n-type semiconductors, and arepreferably selected from fullerenes, substituted fullerenes ornon-fullerene acceptors.

The invention further relates to the use of a compound according to thepresent invention or a composition as described above and below, assemiconducting, charge transporting, electrically conducting,photoconducting, photoactive or light emitting material.

The invention further relates to the use of a compound according to thepresent invention or a composition as described above and below, in anelectronic or optoelectronic device, or in a component of such a deviceor in an assembly comprising such a device.

The invention further relates to a semiconducting, charge transporting,electrically conducting, photoconducting, photoactive or light emittingmaterial, comprising a compound according to the present invention or acomposition as described above and below.

The invention further relates to an electronic or optoelectronic device,or a component thereof, or an assembly comprising it, which comprises acompound according to the present invention or a composition asdescribed above and below.

The invention further relates to an electronic or optoelectronic device,or a component thereof, or an assembly comprising it, which comprises asemiconducting, charge transporting, electrically conducting,photoconducting or light emitting material as described above and below.

The invention further relates to a formulation comprising one or morecompounds according to the present invention, or comprising acomposition or semiconducting material as described above and below, andfurther comprising one or more solvents, preferably selected fromorganic solvents.

The invention further relates to the use of a formulation as describedabove and below for the preparation of an electronic or optoelectronicdevice or a component thereof.

The invention further relates to an electronic or optoelectronic deviceor a component thereof, which is obtained through the use of aformulation as described above and below.

The electronic or optoelectronic device includes, without limitation,organic field effect transistors (OFET), organic thin film transistors(OTFT), organic light emitting diodes (OLED), organic light emittingtransistors (OLET), organic light emitting electrochemical cell (OLEC),organic photovoltaic devices (OPV), organic photodetectors (OPD),organic solar cells, dye-sensitized solar cells (DSSC), organicphotoelectrochemical cells (OPEC), perovskite-based solar cells (PSC),laser diodes, Schottky diodes, photoconductors, photodetectors andthermoelectric devices.

Preferred devices are OFETs, OTFTs, OPVs, PSCs, OPDs and OLEDs, inparticular OPDs and BHJ OPVs or inverted BHJ OPVs.

Further preferred is the use of a compound or composition according tothe present invention as dye in a DSSC or a PSC. Further preferred is aDSSC or PSC comprising a compound or composition according to thepresent invention.

The component of the electronic or optoelectronic device includes,without limitation, charge injection layers, charge transport layers,interlayers, planarising layers, antistatic films, polymer electrolytemembranes (PEM), conducting substrates and conducting patterns.

The assembly comprising an electronic or optoelectronic device includes,without limitation, integrated circuits (IC), radio frequencyidentification (RFID) tags, security markings, security devices, flatpanel displays, backlights of flat panel displays, electrophotographicdevices, electrophotographic recording devices, organic memory devices,sensor devices, biosensors and biochips.

In addition the compounds according to the present invention andcompositions as described above and below can be used as electrodematerials in batteries, or in components or devices for detecting anddiscriminating DNA sequences.

Terms and Definitions

As used herein, the term “polymer” will be understood to mean a moleculeof high relative molecular mass, the structure of which essentiallycomprises multiple repetitions of units derived, actually orconceptually, from molecules of low relative molecular mass (Pure Appl.Chem., 1996, 68, 2291). The term “oligomer” will be understood to mean amolecule of intermediate relative molecular mass, the structure of whichessentially comprises a small plurality of units derived, actually orconceptually, from molecules of lower relative molecular mass (PureAppl. Chem., 1996, 68, 2291). In a preferred meaning as used hereinpresent invention a polymer will be understood to mean a compoundhaving >1, i.e. at least 2 repeat units, preferably ≥5, very preferably≥10, repeat units, and an oligomer will be understood to mean a compoundwith >1 and <10, preferably <5, repeat units.

Further, as used herein, the term “polymer” will be understood to mean amolecule that encompasses a backbone (also referred to as “main chain”)of one or more distinct types of repeat units (the smallestconstitutional unit of the molecule) and is inclusive of the commonlyknown terms “oligomer”, “copolymer”, “homopolymer”, “random polymer” andthe like. Further, it will be understood that the term polymer isinclusive of, in addition to the polymer itself, residues frominitiators, catalysts and other elements attendant to the synthesis ofsuch a polymer, where such residues are understood as not beingcovalently incorporated thereto. Further, such residues and otherelements, while normally removed during post polymerization purificationprocesses, are typically mixed or co-mingled with the polymer such thatthey generally remain with the polymer when it is transferred betweenvessels or between solvents or dispersion media.

As used herein, in a formula showing a polymer or a repeat unit, likefor example a unit of formula I or a polymer of formula III or IV ortheir subformulae, an asterisk (*) will be understood to mean a chemicallinkage to an adjacent unit or to a terminal group in the polymerbackbone. In a ring, like for example a benzene or thiophene ring, anasterisk (*) will be understood to mean a C atom that is fused to anadjacent ring.

As used herein, the terms “repeat unit”, “repeating unit” and “monomericunit” are used interchangeably and will be understood to mean theconstitutional repeating unit (CRU), which is the smallestconstitutional unit the repetition of which constitutes a regularmacromolecule, a regular oligomer molecule, a regular block or a regularchain (Pure Appl. Chem., 1996, 68, 2291). As further used herein, theterm “unit” will be understood to mean a structural unit which can be arepeating unit on its own, or can together with other units form aconstitutional repeating unit.

As used herein, a “terminal group” will be understood to mean a groupthat terminates a polymer backbone. The expression “in terminal positionin the backbone” will be understood to mean a divalent unit or repeatunit that is linked at one side to such a terminal group and at theother side to another repeat unit. Such terminal groups include endcapgroups, or reactive groups that are attached to a monomer forming thepolymer backbone which did not participate in the polymerisationreaction, like for example a group having the meaning of R³¹ or R³² asdefined below.

As used herein, the term “endcap group” will be understood to mean agroup that is attached to, or replacing, a terminal group of the polymerbackbone. The endcap group can be introduced into the polymer by anendcapping process. Endcapping can be carried out for example byreacting the terminal groups of the polymer backbone with amonofunctional compound (“endcapper”) like for example an alkyl- orarylhalide, an alkyl- or arylstannane or an alkyl- or arylboronate. Theendcapper can be added for example after the polymerisation reaction.Alternatively the endcapper can be added in situ to the reaction mixturebefore or during the polymerisation reaction. In situ addition of anendcapper can also be used to terminate the polymerisation reaction andthus control the molecular weight of the forming polymer. Typical endcapgroups are for example H, phenyl and lower alkyl.

As used herein, the term “small molecule” will be understood to mean amonomeric compound which typically does not contain a reactive group bywhich it can be reacted to form a polymer, and which is designated to beused in monomeric form. In contrast thereto, the term “monomer” unlessstated otherwise will be understood to mean a monomeric compound thatcarries one or more reactive functional groups by which it can bereacted to form a polymer.

As used herein, the terms “donor” or “donating” and “acceptor” or“accepting” will be understood to mean an electron donor or electronacceptor, respectively. “Electron donor” will be understood to mean achemical entity that donates electrons to another compound or anothergroup of atoms of a compound. “Electron acceptor” will be understood tomean a chemical entity that accepts electrons transferred to it fromanother compound or another group of atoms of a compound. See alsoInternational Union of Pure and Applied Chemistry, Compendium ofChemical Technology, Gold Book, Version 2.3.2, 19. August 2012, pages477 and 480.

As used herein, the term “n-type” or “n-type semiconductor” will beunderstood to mean an extrinsic semiconductor in which the conductionelectron density is in excess of the mobile hole density, and the term“p-type” or “p-type semiconductor” will be understood to mean anextrinsic semiconductor in which mobile hole density is in excess of theconduction electron density (see also, J. Thewlis, Concise Dictionary ofPhysics, Pergamon Press, Oxford, 1973).

As used herein, the term “leaving group” will be understood to mean anatom or group (which may be charged or uncharged) that becomes detachedfrom an atom in what is considered to be the residual or main part ofthe molecule taking part in a specified reaction (see also Pure Appl.Chem., 1994, 66, 1134).

As used herein, the term “conjugated” will be understood to mean acompound (for example a polymer) that contains mainly C atoms withsp²-hybridisation (or optionally also sp-hybridisation), and whereinthese C atoms may also be replaced by hetero atoms. In the simplest casethis is for example a compound with alternating C—C single and double(or triple) bonds, but is also inclusive of compounds with aromaticunits like for example 1,4-phenylene. The term “mainly” in thisconnection will be understood to mean that a compound with naturally(spontaneously) occurring defects, or with defects included by design,which may lead to interruption of the conjugation, is still regarded asa conjugated compound.

As used herein, unless stated otherwise the molecular weight is given asthe number average molecular weight M_(n) or weight average molecularweight Mw, which is determined by gel permeation chromatography (GPC)against polystyrene standards in eluent solvents such astetrahydrofuran, trichloromethane (TCM, chloroform), chlorobenzene or1,2,4-trichloro-benzene. Unless stated otherwise, chlorobenzene is usedas solvent. The degree of polymerization, also referred to as totalnumber of repeat units, n, will be understood to mean the number averagedegree of polymerization given as n=M_(n)/M_(U), wherein M_(n) is thenumber average molecular weight and M_(U) is the molecular weight of thesingle repeat unit, see J. M. G. Cowie, Polymers: Chemistry & Physics ofModern Materials, Blackie, Glasgow, 1991.

As used herein, the term “carbyl group” will be understood to mean anymonovalent or multivalent organic moiety which comprises at least onecarbon atom either without any non-carbon atoms (like for example—C≡C—), or optionally combined with at least one non-carbon atom such asB, N, O, S, P, Si, Se, As, Te or Ge (for example carbonyl etc.).

As used herein, the term “hydrocarbyl group” will be understood to meana carbyl group that does additionally contain one or more H atoms andoptionally contains one or more hetero atoms like for example B, N, O,S, P, Si, Se, As, Te or Ge.

As used herein, the term “hetero atom” will be understood to mean anatom in an organic compound that is not a H- or C-atom, and preferablywill be understood to mean B, N, O, S, P, Si, Se, Sn, As, Te or Ge.

A carbyl or hydrocarbyl group comprising a chain of 3 or more C atomsmay be linear, branched and/or cyclic, and may include spiro-connectedand/or fused rings.

Preferred carbyl and hydrocarbyl groups include alkyl, alkoxy,thioalkyl, alkylcarbonyl, alkoxycarbonyl, alkylcarbonyloxy andalkoxycarbonyloxy, each of which is optionally substituted and has 1 to40, preferably 1 to 25, very preferably 1 to 18 C atoms, furthermoreoptionally substituted aryl or aryloxy having 6 to 40, preferably 6 to25 C atoms, furthermore alkylaryloxy, arylcarbonyl, aryloxycarbonyl,arylcarbonyloxy and aryloxycarbonyloxy, each of which is optionallysubstituted and has 6 to 40, preferably 7 to 40 C atoms, wherein allthese groups do optionally contain one or more hetero atoms, preferablyselected from B, N, O, S, P, Si, Se, As, Te and Ge.

Further preferred carbyl and hydrocarbyl group include for example: aC₁-C₄₀ alkyl group, a C₁-C₄₀ fluoroalkyl group, a C₁-C₄₀ alkoxy oroxaalkyl group, a C₂-C₄₀ alkenyl group, a C₂-C₄₀ alkynyl group, a C₃-C₄₀allyl group, a C₄-C₄₀ alkyldienyl group, a C₄-C₄₀ polyenyl group, aC₂-C₄₀ ketone group, a C₂-C₄₀ ester group, a C₆-C₁₈ aryl group, a C₆-C₄₀alkylaryl group, a C₆-C₄₀ arylalkyl group, a C₄-C₄₀ cycloalkyl group, aC₄-C₄₀ cycloalkenyl group, and the like. Preferred among the foregoinggroups are a C₁-C₂₀ alkyl group, a C₁-C₂₀ fluoroalkyl group, a C₂-C₂₀alkenyl group, a C₂-C₂₀ alkynyl group, a C₃-C₂₀ allyl group, a C₄-C₂₀alkyldienyl group, a C₂-C₂₀ ketone group, a C₂-C₂₀ ester group, a C₆-C₁₂aryl group, and a C₄-C₂₀ polyenyl group, respectively.

Also included are combinations of groups having carbon atoms and groupshaving hetero atoms, like e.g. an alkynyl group, preferably ethynyl,that is substituted with a silyl group, preferably a trialkylsilylgroup.

The carbyl or hydrocarbyl group may be an acyclic group or a cyclicgroup. Where the carbyl or hydrocarbyl group is an acyclic group, it maybe linear or branched. Where the carbyl or hydrocarbyl group is a cyclicgroup, it may be a non-aromatic carbocyclic or heterocyclic group, or anaryl or heteroaryl group.

A non-aromatic carbocyclic group as referred to above and below issaturated or unsaturated and preferably has 4 to 30 ring C atoms. Anon-aromatic heterocyclic group as referred to above and belowpreferably has 4 to 30 ring C atoms, wherein one or more of the C ringatoms are optionally replaced by a hetero atom, preferably selected fromN, O, P, S, Si and Se, or by a —S(O)— or —S(O)₂— group. The non-aromaticcarbo- and heterocyclic groups are mono- or polycyclic, may also containfused rings, preferably contain 1, 2, 3 or 4 fused or unfused rings, andare optionally substituted with one or more groups L, wherein

L is selected from F, Cl, —CN, —NC, —NCO, —NCS, —OCN, —SCN, —R⁰, —OR⁰,—SR⁰, —C(═O)X⁰, —C(═O)R⁰, —C(═O)—OR⁰, —O—C(═O)—R⁰, —NH₂, —NHR⁰, —NR⁰R⁰⁰,—C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰, —SO₃R⁰, —SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, oroptionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30,preferably 1 to 20 C atoms that is optionally substituted and optionallycomprises one or more hetero atoms, wherein X⁰ is halogen, preferably For Cl, and R⁰, R⁰⁰ denote H or linear or branched alkyl with 1 to 20,preferably 1 to 12 C atoms that is optionally fluorinated.

Preferably L is selected from F, —CN, R⁰, —OR⁰, —SR⁰, —C(═O)—R⁰,—C(═O)—OR⁰, —O—C(═O)—R⁰, —O—C(═O)—OR⁰, —C(═O)—NHR⁰ and —C(═O)—NR⁰R⁰⁰.

Further preferably L is selected from F or alkyl, alkoxy, oxaalkyl,thioalkyl, fluoroalkyl, fluoroalkoxy, alkylcarbonyl, alkoxycarbonyl,with 1 to 12 C atoms, or alkenyl or alkynyl with 2 to 12 C atoms.

Preferred non-aromatic carbocyclic or heterocyclic groups aretetrahydrofuran, indane, pyran, pyrrolidine, piperidine, cyclopentane,cyclohexane, cycloheptane, cyclopentanone, cyclohexanone,dihydro-furan-2-one, tetrahydro-pyran-2-one and oxepan-2-one.

An aryl group as referred to above and below preferably has 4 to 30 ringC atoms, is mono- or polycyclic and may also contain fused rings,preferably contains 1, 2, 3 or 4 fused or unfused rings, and isoptionally substituted with one or more groups L as defined above.

A heteroaryl group as referred to above and below preferably has 4 to 30ring C atoms, wherein one or more of the C ring atoms are replaced by ahetero atom, preferably selected from N, O, S, Si and Se, is mono- orpolycyclic and may also contain fused rings, preferably contains 1, 2, 3or 4 fused or unfused rings, and is optionally substituted with one ormore groups L as defined above.

An arylalkyl or heteroarylalkyl group as referred to above and belowpreferably denotes —(CH₂)_(a)-aryl or —(CH₂)_(a)-heteroaryl, wherein ais an integer from 1 to 6, preferably 1, and “aryl” and “heteroaryl”have the meanings given above and below. A preferred arylalkyl group isbenzyl which is optionally substituted by L.

As used herein, “arylene” will be understood to mean a divalent arylgroup, and “heteroarylene” will be understood to mean a divalentheteroaryl group, including all preferred meanings of aryl andheteroaryl as given above and below.

Preferred aryl and heteroaryl groups are phenyl in which, in addition,one or more CH groups may be replaced by N, naphthalene, thiophene,selenophene, thienothiophene, dithienothiophene, fluorene and oxazole,all of which can be unsubstituted, mono- or polysubstituted with L asdefined above. Very preferred aryl and heteroaryl groups are selectedfrom pyrrole, preferably N-pyrrole, furan, pyridine, preferably 2- or3-pyridine, pyrimidine, pyridazine, pyrazine, triazole, tetrazole,pyrazole, imidazole, isothiazole, thiazole, thiadiazole, isoxazole,oxazole, oxadiazole, thiophene, preferably 2-thiophene, selenophene,preferably 2-selenophene, 2,5-dithiophene-2′,5′-diyl,thieno[3,2-b]thiophene, thieno[2,3-b]thiophene, furo[3,2-b]furan,furo[2,3-b]furan, seleno[3,2-b]selenophene, seleno[2,3-b]selenophene,thieno[3,2-b]selenophene, thieno[3,2-b]furan, indole, isoindole,benzo[b]furan, benzo[b]thiophene, benzo[1,2-b;4,5-b′]dithiophene,benzo[2,1-b;3,4-b′]dithiophene, quinole, 2-methylquinole, isoquinole,quinoxaline, quinazoline, benzotriazole, benzimidazole, benzothiazole,benzisothiazole, benzisoxazole, benzoxadiazole, benzoxazole,benzothiadiazole, 4H-cyclopenta[2,1-b;3,4-b′]dithiophene,7H-3,4-dithia-7-sila-cyclopenta[a]pentalene, all of which can beunsubstituted, mono- or polysubstituted with L as defined above. Furtherexamples of aryl and heteroaryl groups are those selected from thegroups shown hereinafter.

An alkyl group or an alkoxy group, i.e., where the terminal CH₂ group isreplaced by —O—, can be linear or branched. Particularly preferredlinears have 2, 3, 4, 5, 6, 7, 8, 12 or 16 carbon atoms and accordinglydenote preferably ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl,dodecyl or hexadecyl, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy,octoxy, dodecoxy or hexadecoxy, furthermore methyl, nonyl, decyl,undecyl, tridecyl, tetradecyl, pentadecyl, nonoxy, decoxy, undecoxy,tridecoxy or tetradecoxy, for example.

An alkenyl group, i.e., wherein one or more CH₂ groups are replaced by—CH═CH— can be linear or branched. It is preferably linear, has 2 to 10C atoms and accordingly is preferably vinyl, prop-1-, or prop-2-enyl,but-1-, 2- or but-3-enyl, pent-1-, 2-, 3- or pent-4-enyl, hex-1-, 2-,3-, 4- or hex-5-enyl, hept-1-, 2-, 3-, 4-, 5- or hept-6-enyl, oct-1-,2-, 3-, 4-, 5-, 6- or oct-7-enyl, non-1-, 2-, 3-, 4-, 5-, 6-, 7- ornon-8-enyl, dec-1-, 2-, 3-, 4-, 5-, 6-, 7-, 8- or dec-9-enyl.

Especially preferred alkenyl groups are C₂-C₇-1E-alkenyl,C₄-C₇-3E-alkenyl, C₅-C₇-4-alkenyl, C₆-C₇-5-alkenyl and C₇-6-alkenyl, inparticular C₂-C₇-1E-alkenyl, C₄-C₇-3E-alkenyl and C₅-C₇-4-alkenyl.Examples for particularly preferred alkenyl groups are vinyl,1E-propenyl, 1E-butenyl, 1E-pentenyl, 1E-hexenyl, 1E-heptenyl,3-butenyl, 3E-pentenyl, 3E-hexenyl, 3E-heptenyl, 4-pentenyl, 4Z-hexenyl,4E-hexenyl, 4Z-heptenyl, 5-hexenyl, 6-heptenyl and the like. Groupshaving up to 5 C atoms are generally preferred.

An oxaalkyl group, i.e., where one CH₂ group is replaced by —O—, can belinear. Particularly preferred linear groups are 2-oxapropyl(=methoxymethyl), 2-(=ethoxymethyl) or 3-oxabutyl (=2-methoxyethyl), 2-,3-, or 4-oxapentyl, 2-, 3-, 4-, or 5-oxahexyl, 2-, 3-, 4-, 5-, or6-oxaheptyl, 2-, 3-, 4-, 5-, 6- or 7-oxaoctyl, 2-, 3-, 4-, 5-, 6-, 7- or8-oxanonyl or 2-, 3-, 4-, 5-, 6-, 7-, 8- or 9-oxadecyl, for example.

In an alkyl group wherein one CH₂ group is replaced by —O— and one CH₂group is replaced by —C(O)—, these radicals are preferably neighboured.

Accordingly these radicals together form a carbonyloxy group —C(O)—O— oran oxycarbonyl group —O—C(O)—. Preferably this group is linear and has 2to 6 C atoms. It is accordingly preferably acetyloxy, propionyloxy,butyryloxy, pentanoyloxy, hexanoyloxy, acetyloxymethyl,propionyloxymethyl, butyryloxymethyl, pentanoyloxymethyl,2-acetyloxyethyl, 2-propionyloxy-ethyl, 2-butyryloxyethyl,3-acetyloxypropyl, 3-propionyloxypropyl, 4-acetyloxybutyl,methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl,pentoxycarbonyl, methoxycarbonylmethyl, ethoxy-carbonylmethyl,propoxycarbonylmethyl, butoxycarbonylmethyl, 2-(methoxycarbonyl)ethyl,2-(ethoxycarbonyl)ethyl, 2-(propoxy-carbonyl)ethyl,3-(methoxycarbonyl)propyl, 3-(ethoxycarbonyl)propyl,4-(methoxycarbonyl)-butyl.

An alkyl group wherein two or more CH₂ groups are replaced by —O— and/or—C(O)O— can be linear or branched. It is preferably linear and has 3 to12 C atoms. Accordingly, it is preferably bis-carboxy-methyl,2,2-bis-carboxy-ethyl, 3,3-bis-carboxy-propyl, 4,4-bis-carboxy-butyl,5,5-bis-carboxy-pentyl, 6,6-bis-carboxy-hexyl, 7,7-bis-carboxy-heptyl,8,8-bis-carboxy-octyl, 9,9-bis-carboxy-nonyl, 10,10-bis-carboxy-decyl,bis-(methoxycarbonyl)-methyl, 2,2-bis-(methoxycarbonyl)-ethyl,3,3-bis-(methoxycarbonyl)-propyl, 4,4-bis-(methoxycarbonyl)-butyl,5,5-bis-(methoxycarbonyl)-pentyl, 6,6-bis-(methoxycarbonyl)-hexyl,7,7-bis-(methoxycarbonyl)-heptyl, 8,8-bis-(methoxycarbonyl)-octyl,bis-(ethoxycarbonyl)-methyl, 2,2-bis-(ethoxycarbonyl)-ethyl,3,3-bis-(ethoxycarbonyl)-propyl, 4,4-bis-(ethoxycarbonyl)-butyl,5,5-bis-(ethoxycarbonyl)-hexyl.

A thioalkyl group, i.e., where one CH₂ group is replaced by —S—, ispreferably linear thiomethyl (—SCH₃), 1-thioethyl (—SCH₂CH₃),1-thiopropyl (=—SCH₂CH₂CH₃), 1-(thiobutyl), 1-(thiopentyl),1-(thiohexyl), 1-(thioheptyl), 1-(thiooctyl), 1-(thiononyl),1-(thiodecyl), 1-(thioundecyl) or 1-(thiododecyl), wherein preferablythe CH₂ group adjacent to the sp² hybridised vinyl carbon atom isreplaced.

A fluoroalkyl group can either be perfluoroalkyl C_(i)F_(2i+1), whereini is an integer from 1 to 15, in particular CF₃, C₂F₅, C₃F₇, C₄F₉,C₅F₁₁, C₆F₁₃, C₇F₁₅ or C₈F₁₇, very preferably C₆F₁₃, or partiallyfluorinated alkyl, preferably with 1 to 15 C atoms, in particular1,1-difluoroalkyl, all of the aforementioned being linear or branched.

Preferably “fluoroalkyl” means a partially fluorinated (i.e. notperfluorinated) alkyl group.

Alkyl, alkoxy, alkenyl, oxaalkyl, thioalkyl, carbonyl and carbonyloxygroups can be achiral or chiral groups. Particularly preferred chiralgroups are 2-butyl (=1-methylpropyl), 2-methylbutyl, 2-methylpentyl,3-methylpentyl, 2-ethylhexyl, 2-butyloctyl, 2-hexyldecyl,2-octyldodecyl, 3,7-dimethyloctyl, 3,7,11-trimethyldodecyl,2-propylpentyl, in particular 2-methylbutyl, 2-methylbutoxy,2-methylpentoxy, 3-methyl-pentoxy, 2-ethyl-hexoxy, 2-butyloctoxyo,2-hexyldecoxy, 2-octyldodecoxy, 3,7-dimethyloctoxy,3,7,11-trimethyldodecoxy, 1-methylhexoxy, 2-octyloxy,2-oxa-3-methylbutyl, 3-oxa-4-methyl-pentyl, 4-methylhexyl, 2-hexyl,2-octyl, 2-nonyl, 2-decyl, 2-dodecyl, 6-methoxy-octoxy, 6-methyloctoxy,6-methyloctanoyloxy, 5-methylheptyloxy-carbonyl, 2-methylbutyryloxy,3-methylvaleroyloxy, 4-methylhexanoyloxy, 2-chloro-propionyloxy,2-chloro-3-methylbutyryloxy, 2-chloro-4-methyl-valeryl-oxy,2-chloro-3-methylvaleryloxy, 2-methyl-3-oxapentyl, 2-methyl-3-oxa-hexyl,1-methoxypropyl-2-oxy, 1-ethoxypropyl-2-oxy, 1-propoxypropyl-2-oxy,1-butoxypropyl-2-oxy, 2-fluorooctyloxy, 2-fluorodecyloxy,1,1,1-trifluoro-2-octyloxy, 1,1,1-trifluoro-2-octyl,2-fluoromethyloctyloxy for example. Very preferred are 2-methylbutyl,2-ethylhexyl, 2-butyloctyl, 2-hexyldecyl, 2-octyldodecyl,3,7-dimethyloctyl, 3,7,11-trimethyldodecyl, 2-hexyl, 2-octyl,2-octyloxy, 1,1,1-trifluoro-2-hexyl, 1,1,1-trifluoro-2-octyl and1,1,1-trifluoro-2-octyloxy.

Preferred achiral branched groups are isopropyl, isobutyl(=methylpropyl), isopentyl (=3-methylbutyl), tert. butyl, isopropoxy,2-methyl-propoxy and 3-methylbutoxy.

In a preferred embodiment, the substituents on an aryl or heteroarylring are independently of each other selected from primary, secondary ortertiary alkyl, alkoxy, oxaalkyl, thioalkyl, alkylcarbonyl oralkoxycarbonyl with 1 to 30 C atoms, wherein one or more H atoms areeach optionally replaced by F, or aryl, aryloxy, heteroaryl orheteroaryloxy that is optionally alkylated, alkoxylated, alkylthiolatedor esterified and has 4 to 30, preferably 5 to 20, ring atoms. Furtherpreferred substituents are selected from the group consisting of thefollowing formulae

wherein RSub₁₋₃ each denote L as defined above and below and where atleast, preferably all, of RSub₁₋₃ is alkyl, alkoxy, oxaalkyl, thioalkyl,alkylcarbonyl or alkoxycarbonyl with up to 24 C atoms, preferably up to20 C atoms, that is optionally fluorinated, and wherein the dashed linedenotes the link to the ring to which these groups are attached. Verypreferred among these substituents are those wherein all RSub₁₋₃subgroups are identical.

As used herein, if an aryl(oxy) or heteroaryl(oxy) group is “alkylatedor alkoxylated”, this means that it is substituted with one or morealkyl or alkoxy groups having from 1 to 24 C-atoms and beingstraight-chain or branched and wherein one or more H atoms are eachoptionally substituted by an F atom.

Above and below, Y¹ and Y² are independently of each other H, F, Cl orCN.

As used herein, —CO—, —C(═O)— and —C(O)— will be understood to mean acarbonyl group, i.e. a group having the structure

As used herein, C═CR¹R² will be understood to mean a group having thestructure

As used herein, “halogen” includes F, Cl, Br or I, preferably F, Cl orBr. A halogen atom that represents a substituent on a ring or chain ispreferably F or Cl, very preferably F. A halogen atom that represents areactive group in a monomer or an intermediate is preferably Br or I.

Above and below, the term “mirror image” means a moiety that can beobtained from another moiety by flipping it vertically or horizontallyacross an external symmetry plane or a symmetry plane extending throughthe moiety. For example the moiety

also includes the mirror images

DETAILED DESCRIPTION

The compounds of the present invention are easy to synthesize andexhibit advantageous properties. They show good processibility for thedevice manufacture process, high solubility in organic solvents, and areespecially suitable for large scale production using solution processingmethods.

Co-polymers derived from monomers of the present invention and electronacceptor monomers show low bandgaps, high charge carrier mobilities,high external quantum efficiencies in BHJ solar cells, good morphologywhen used in p/n-type blends e.g. with fullerenes, high oxidativestability, a long lifetime in electronic devices, and are promisingmaterials for organic electronic OE devices, especially for OPV deviceswith high power conversion efficiency.

The compounds of the present invention are especially suitable as bothp-type and n-type semiconductors, depending on the nature of theco-monomer or π-units cross-coupled to extend the conjugation, for thepreparation of blends of p-type and n-type semiconductors which aresuitable for use in BHJ photovoltaic devices.

The compounds according to the present invention are further suitable toreplace the fullerene compounds that have hitherto been used as n-typesemiconductor in OPV or OPD devices.

Besides, the compounds according to the present invention show thefollowing advantageous properties:

-   i) The use of two different halogen substituents X¹ and X² allows to    fine tune the electronic properties of the compounds.-   ii) In case of a conjugated polymer, the use of two different    halogen substituents X¹ and X² is expected to imply a significant    change of the morphology of the active layer in an OE device. Thus,    inclusion of the chlorine atom having a higher atomic radius than    fluorine allows to modify, e.g. decrease, the packing strength of    the polymer chains. In a BHJ this allows a better intermixing of the    two phases within the blend, which is expected to lead to a better    overall charge dissociation and hence an increase in power    conversion efficiencies when used in solar cells.-   iii) The decrease of packing strength is also expected to lead to a    better solubility, and consequently better processability, of the    material which is especially advantageous for large scale module    production.

The synthesis of the compounds according to the present invention can beachieved based on methods that are known to the skilled person anddescribed in the literature, as will be further illustrated herein.

In the units of formula I and its subformulae U is preferably S or NR,very preferably S.

In the units of formula I and its subformulae R is preferably H orlinear, branched or cyclic alkyl with 1 to 30, preferably 1 to 20, Catoms, in which one or more CH₂ groups are optionally replaced by —O—,—S—, —C(═O—, C(═O)—O—, —O—C(═O)—, —CF₂— or —CH═CH—, and very preferablyH or linear or branched alkyl with 1 to 20 C atoms that is optionallyfluorinated.

The compounds according to the present invention include smallmolecules, monomers, oligomers and polymers.

A preferred embodiment of the present invention relates to a conjugatedpolymer comprising one or more repeating units of formula I. Preferablythe conjugated polymer according to this preferred embodiment furthercomprises one or more arylene or heteroarylene units that have from 5 to20 ring atoms, are mono- or polycyclic, optionally contains fused rings,and are unsubstituted or substituted by one or more identical ordifferent groups L, preferably by one or more identical or differentgroups R^(S), as defined above and below.

Preferably the conjugated polymer according to this preferred embodimentcomprises, preferably consists of, one or more repeating units offormula II1 or II2, and optionally one or more repeating units offormula II3:

—(Ar¹)_(a)—U—(Ar²)_(b)—(Ar³)_(c)—(Ar⁴)_(d)—  I11

—(Ar¹)_(a)—(Ar²)_(b)—U—(Ar³)_(c)—(Ar⁴)_(d)—  II2

—(Ar¹)_(a)—(Ar²)_(b)—(Ar³)_(c)—(Ar⁴)_(d)—  II3

wherein the individual radicals, independently of each other and on eachoccurrence identically or differently, have the following meanings

-   U a unit of formula I as defined above and below,-   Ar¹⁻⁴ arylene or heteroarylene that has 5 to 20 ring atoms, is mono-    or polycyclic, does optionally contain fused rings, is unsubstituted    or substituted by one or more identical or different groups R^(S),    and is different from formula I, or CY¹═CY²— or —C≡C—,-   R^(S) F, Cl, CN, or linear, branched or cyclic alkyl with 1 to 30,    preferably 1 to 20, C atoms, in which one or more CH₂ groups are    optionally replaced by —O—, —S—, —C(═O)—, —C(═S)—, —C(═O)—O—,    —O—C(═O)—, —NR⁰—, —SiR⁰R⁰⁰—, —CF₂—, —CR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C—    in such a manner that O and/or S atoms are not linked directly to    one another, and in which one or more H atoms are optionally    replaced by F, Cl, Br, I or CN, and in which one or more CH₂ or CH₃    groups are optionally replaced by a cationic or anionic group, or    R^(S) is aryl, heteroaryl, arylalkyl, heteroarylalkyl, aryloxy or    heteroaryloxy, wherein each of the aforementioned cyclic groups has    5 to 20 ring atoms, is mono- or polycyclic, does optionally contain    fused rings, and is unsubstituted or substituted by one or more    identical or different groups L as defined above,-   X⁰ halogen, preferably F or Cl,-   Y¹, Y²H, F, Cl or CN,-   R⁰, R⁰⁰H or linear or branched alkyl with 1 to 20, preferably 1 to    12, C atoms that is optionally fluorinated,-   a, b, c, d 0 or 1, wherein in formula II3 a+b+c+d≥1.

Preferably the conjugated polymer comprises one or more repeating unitsof formula II1 or II2 wherein a+b+c+d≥1.

Further preferably the conjugated polymer comprises one or morerepeating units of formula II1 wherein b=1 and a=c=d=0 and one or morerepeating units of formula II3 wherein a=b=1 and c=d=0.

Further preferably the conjugated polymer comprises two or more distinctrepeating units of formula II1 wherein b=1 and a=c=d=0.

Further preferably at least one of Ar¹, Ar², Ar³ and Ar⁴ is an aryleneor heteroarylene group as being defined in formula II1 and havingelectron donor property.

Very preferably the conjugated polymer comprises at least one electrondonating unit (“donor unit”) and at least one electron accepting unit(“acceptor unit”), and optionally at least one spacer unit separating adonor unit from an acceptor unit, wherein each donor and acceptor unitsis directly connected to another donor or acceptor unit or to a spacerunit, and wherein all of the donor, acceptor and spacer units areselected from arylene or heteroarylene that has from 5 to 20 ring atoms,is mono- or polycyclic, optionally contains fused rings, are isunsubstituted or substituted by one or more identical or differentgroups R^(S) as defined above, and wherein at least one of the acceptorunits is a unit of formula I.

Preferably the spacer units, if present, are located between the donorand acceptor units such that a donor unit and an acceptor unit are notdirectly connected to each other.

Preferably the conjugated polymer comprises, very preferably consistsof, one or more repeating units selected from formula U1-U4, and/or oneor more repeating units selected from formulae U5-U7

-(A)-  U1

-(A-Sp)-  U2

-(A-D)-  U3

-(Sp-A-Sp)-  U4

-(D)-  U5

-(D-Sp)-  U6

-(Sp-D-Sp)-  U7

wherein D denotes a donor unit, A denotes an acceptor unit and Spdenotes a spacer unit, all of which are selected, independently of eachother and on each occurrence identically or differently, from arylene orheteroarylene that has from 5 to 20 ring atoms, is mono- or polycyclic,optionally contains fused rings, are is unsubstituted or substituted byone or more identical or different groups R^(S) as defined above, andthe polymer contains at least one repeating unit of formulae U1-U4wherein A is a unit of formula I.

Very preferred are conjugated polymers of formula Pi-Piv

-[(D-Sp)_(x)-(A-Sp)_(y)]_(n)-  Pi

-[(A-D)_(x)-(A-Sp)_(y)]_(n)-  Pi

-[(D)_(x)-(Sp-A-Sp)_(y)]_(n)-  Piii

-[D-Sp-A-Sp]_(n)-  Piv

-[D-A]_(n)-  Pv

-[D-Sp-A-Sp]_(n)  Pvi

-[D¹-A-D²-A]_(n)  Pvii

-[D-A¹-D-A²]_(n)  Pviii

wherein A, D and Sp are as defined in formula U1-U7, A and D can each,in case of multiple occurrence, also have different meanings, D¹ and D²have one of the meanings given for D and are different from each other,A¹ and A² have one of the meanings given for A and are different fromeach other, x and y denote the molar fractions of the correspondingunits, x and y are each, independently of one another, a non-integer>0and <1, with x+y=1, and n is an integer>1.

In another preferred embodiment of the present invention R^(S), on eachoccurrence identically or differently, denotes F, Cl or linear, branchedor cyclic alkyl with 1 to 30, preferably 1 to 20, C atoms, in which oneor more CH₂ groups are optionally replaced by —O—, —S—, —C(═O—,C(═O)—O—, —O—C(═O)—, —CF₂— or —CH═CH—, and very preferably linear orbranched alkyl, alkoxy, oxaalkyl, thioalkyl, alkylcarbonyl oralkylcarbonyloxy with 1 to 30, preferably 1 to 20 C atoms that isoptionally fluorinated.

In another preferred embodiment of the present invention R^(S), on eachoccurrence identically or differently, denotes aryl, aryloxy, heteroarylor heteroaryloxy, each of which has 5 to 20 ring atoms and optionallycontains fused rings and is unsubstituted or substituted by one or moregroups L as defined above. Very preferably R^(S) according to thispreferred embodiment is selected from phenyl, pyrrole, furan, pyridine,thiazole, thiophene, thiadiazole, triazole, pyrazine,thieno[3,2-b]thiophene or thieno[2,3-b]thiophene, each of which isunsubstituted or substituted with F or alkyl, alkoxy or thioalkyl having1 to 20 C atoms and being optionally fluorinated.

Preferably R^(S) in the formulae above and below is selected, on eachoccurrence identically or differently, from the following groups:

-   a) the group consisting of linear or branched alkyl, alkoxy,    oxaalkyl, thioalkyl, alkylcarbonyl or alkoxycarbonyl with 1 to 24 C    atoms, preferably 1 to 20 C atoms, that is optionally fluorinated,    preferably selected from formulae SUB1-SUB6 above,-   b) the group consisting of aryl and heteroaryl that has 5 to 20 ring    atoms, is mono- or polycyclic, does optionally contain fused rings,    and is unsubstituted or substituted by one or more identical or    different groups, L as defined in formula II1, very preferably    phenyl or thiophene that is optionally substituted with alkyl or    alkoxy having 1 to 20 C atoms that is optionally fluorinated,    preferably selected from formulae SUB7-SUB18 above,-   c) the group consisting of F, Cl and CN.

In another preferred embodiment of the present invention, R^(S) denotes,on each occurrence identically or differently, straight-chain, branchedor cyclic alkyl with 1 to 20 C-atoms wherein one or more CH₂ or CH₃groups are substituted by a cationic or anionic group.

The cationic group is preferably selected from the group consisting ofphosphonium, sulfonium, ammonium, uronium, thiouronium, guanidinium orheterocyclic cations such as imidazolium, pyridinium, pyrrolidinium,triazolium, morpholinium or piperidinium cation.

Preferred cationic groups are selected from the group consisting oftetraalkylammonium, tetraalkylphosphonium, N-alkylpyridinium,N,N-dialkylpyrrolidinium, 1,3-dialkylimidazolium, wherein “alkyl”preferably denotes a straight-chain or branched alkyl group with 1 to 12C atoms.

Further preferred cationic groups are selected from the group consistingof the following formulae

wherein R^(1′), R^(2′), R^(3′) and R^(4′) denote, independently of eachother, H, a straight-chain or branched alkyl group with 1 to 12 C atomsor non-aromatic carbo- or heterocyclic group or an aryl or heteroarylgroup, each of the aforementioned groups having 3 to 20, preferably 5 to15, ring atoms, being mono- or polycyclic, and optionally beingsubstituted by one or more identical or different substituents L asdefined below, or denote a link to the respective group R^(S).

In the above cationic groups of the above-mentioned formulae any one ofthe groups R^(1′), R^(2′), R^(3′) and R^(4′) (if they replace a CH₃group) can denote a link to the group R¹, or two neighbored groupsR^(1′), R^(2′), R^(3′) or R^(4′) (if they replace a CH₂ group) candenote a link to the respective group R^(S).

The anionic group is preferably selected from the group consisting ofborate, imide, phosphate, sulfonate, sulfate, succinate, naphthenate orcarboxylate, very preferably from phosphate, sulfonate or carboxylate.

In the polymers according to the present invention, the total number ofrepeating units n is preferably from 2 to 10,000. The total number ofrepeating units n is preferably ≥5, very preferably ≥10, most preferably≥50, and preferably ≤500, very preferably ≤1,000, most preferably≤2,000, including any combination of the aforementioned lower and upperlimits of n.

The polymers of the present invention include homopolymers andcopolymers, like statistical or random copolymers, alternatingcopolymers and block copolymers, as well as combinations thereof.

The conjugated polymers are preferably statistical copolymers.

Especially preferred are repeating units and polymers of formulae U1-U7and Pi-viii wherein D, D¹ and D² are selected from the group consistingof the following formulae

wherein R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ independently of eachother, and on each occurrence identically or differently, denote H orhave one of the meanings of R^(S) as defined in formula II1 or one ofits preferred meanings as given above and below.

Preferred donor units D are selected from formulae D1, D7, D10, D11,D19, D22, D29, D30, D35, D36, D37, D44, D55, D84, D87, D88, D89, D93,D94, D106, D11, D119, D139, D140, D141, D146, D147 and D150 whereinpreferably at least one of R¹¹, R¹², R¹³ and R¹⁴ is different from H.

Especially preferred are repeating units of formulae II1-II3 wherein oneor more groups Ar¹⁻⁴ are selected from the group consisting formulaeD1-D151, preferably of formulae D1, D7, D10, D11, D19, D22, D29, D30,D35, D36, D37, D44, D55, D84, D87, D88, D89, D93, D94, D106, D111, D119,D139, D140, D141, D146, D147 and D150 wherein preferably at least one ofR¹¹, R¹², R¹³ and R¹⁴ is different from H and in formula D150 preferablyR¹² and R¹³ are F and R¹¹ and R¹⁴ are H or C₁-C₃₀ alkyl.

Further preferred are repeating units and polymers of formulae U1-U7 andPi-viii wherein A, A¹ and A² are selected from the group consisting ofthe following formulae

wherein R¹¹, R¹², R¹³, R¹⁴, R¹⁵ and R¹⁶ independently of each other, andon each occurrence identically or differently, denote H or have one ofthe meanings of R^(S) as defined in formula II1 or one of its preferredmeanings as given above and below, and in unit A1 R¹¹ and R¹² havemeanings that are different from X¹ and X² in as defined in formula I.

Preferred acceptor units A are selected from formulae A1, A5, A6, A7,A15, A16, A20, A74, A88, A92, A94, A98, A99, A100 and A103, whereinpreferably at least one of R¹¹, R¹², R¹³ and R¹⁴ is different from H.

Especially preferred are repeating units of formulae II1-II3 wherein oneor more groups Ar¹⁻⁴ are selected from the group consisting formulaeA1-A103, preferably of formulae A1, A5, A6, A7, A15, A16, A20, A74, A88,A92, A94, A98, A99, A100 and A103, wherein preferably at least one ofR¹¹, R¹², R¹³ and R¹⁴ is different from H.

Further preferred are repeating units and polymers of formulae U1-U7 andPi-Pviii wherein Sp is selected from the group consisting of thefollowing formulae

wherein R¹¹, R¹², R¹³, R¹⁴ independently of each other, and on eachoccurrence identically or differently, denote H or have one of themeanings of R^(S) as defined in formula II1.

In the formulae Sp1 to Sp17 preferably R¹¹ and R¹² are H. In formulaSp18 preferably R¹¹⁻¹⁴ are H or F.

Very preferred units Sp are selected from formulae Sp1, Sp2, Sp6, Sp10,Sp11, Sp12, Sp13 and Sp14, most preferably form formulae Sp1, Sp6, Sp10and Sp14, wherein preferably one of R¹¹ and R¹² is H or both R¹¹ and R¹²are H.

Especially preferred are repeating units of formulae II1-II3 wherein oneor more groups Ar¹⁻⁴, independently of each other and on each occurrenceidentically or differently, are selected from the group consistingformulae Sp1-Sp18, preferably of formulae Sp1, Sp2, Sp6, Sp10, Sp11,Sp12, Sp13 and Sp14, most preferably form formulae Sp1, Sp6, Sp10 andSp14, wherein preferably one of R¹¹ and R¹² is H or both R¹¹ and R¹² areH.

Further preferred are repeating units and polymers of formulae U1-U7 andPi-Piv wherein

-   a) one or more, preferably all, groups D are selected from the group    consisting of the formulae D1-D151, very preferably of the formulae    D1, D7, D10, D11, D19, D22, D29, D30, D35, D36, D37, D44, D55, D84,    D87, D88, D89, D93, D94, D106, D111, D119, D139, D140, D141, D146,    D147 and D150, and/or-   b) one or more, preferably all, groups A are selected from the group    consisting of the formulae A1-A103, very preferably of the formulae    A1, A5, A6, A7, A15, A16, A20, A36, A74, A84, A88, A92, A94, A98,    A99, A100 and A103,    -   and-   c) one or more, preferably all, groups Sp are selected from the    group consisting of the formulae Sp1-Sp18, very preferably of the    formulae Sp1, Sp2, Sp6, Sp10, Sp11, Sp12, Sp13 and Sp14.

Preferably the conjugated polymer contains, preferably consists of, oneor more units of formula I and

-   a) one or more donor units D selected from the group consisting of    the formulae D1, D7, D10, D11, D19, D22, D29, D30, D35, D36, D37,    D44, D55, D84, D87, D88, D89, D93, D94, D106, D111, D119, D139,    D140, D141, D146, D147 and D150 and/or-   b) one or more acceptor units A selected from the group consisting    of the formulae A1, A5, A6, A7, A15, A16, A20, A74, A88, A92, A94,    A98, A99, A100 and A103,    -   and-   c) optionally one or more spacer units Sp selected from the group    consisting of the formulae Sp1-Sp18, very preferably of the formulae    Sp1, Sp6, Sp10 and Sp14,    wherein the spacer units, if present, are preferably located between    the donor and acceptor units such that a donor unit and an acceptor    unit are not directly connected to each other.

Very preferred conjugated polymers are selected from the followingformulae

wherein R¹¹⁻¹⁸, x, y and n are as defined above, w and z have one of themeanings given for y, x+y+w+z=1, a, b, c and d are independently of eachother 0 or 1, X¹ and X² are as defined in formula I, one of X³ and X⁴ isF and the other is Cl, and X¹¹, X¹², X¹³ and X¹⁴ denote independently ofeach other H, F or Cl.

In formula P3 and P34 preferably R¹⁷ and R¹⁸ are F. Further preferablyin formula P3 and P34 one or both of R¹¹ and R¹² are C₁-C₃₀ alkyl.

Further preferred are polymers comprising one or more repeating unitsselected from formulae P1-P34 wherein n is 1.

In the polymers of formula Pi-iv and P1-P34 which are composed of twobuilding blocks [ ]_(x) and [ ]_(y), x and y are preferably anon-integer from 0.1 to 0.9, very preferably from 0.25 to 0.75, mostpreferably from 0.4 to 0.6.

In the polymers of formula Pi-iv and P1-P34 which are composed of threebuilding blocks [ ]_(x), [ ]_(y), and [ ]_(z), x, y and z are preferablya non-integer from 0.1 to 0.8, very preferably from 0.2 to 0.6, mostpreferably from 0.25 to 0.4.

In the polymers of formula Pi-iv and P1-P34 which are composed of fourbuilding blocks [ ]_(w), [ ]_(x), [ ]_(y), and [ ]_(z), w, x, y and zare preferably a non-integer from 0.1 to 0.6, very preferably from 0.15to 0.4, most preferably from 0.2 to 0.3.

In the formulae P1-P34 preferably one or more of X¹¹, X¹², X¹³ and X¹⁴denote F, very preferably all of X¹¹, X¹², X¹³ and X¹⁴ denote F or X¹¹and X¹² denote H and X¹³ and X¹⁴ denote F.

In the formulae P1-P34 containing a benzodithiophene (BDT) group,preferably R¹⁵ and R¹⁶ on the BDT group are H, and R¹³ and R¹⁴ on theBDT group are different from H.

In the formulae P1-P34 containing a thiophene group that is onlymonosubstituted by R¹¹ or R¹², said group R¹¹ or R¹² is preferablydifferent from H.

In the formulae P1-P34, preferably R¹¹⁻¹⁶, when being different from H,are selected from the following groups:

-   a) the group consisting of linear or branched alkyl, alkoxy or    sulfanylalkyl with 1 to 30, preferably 1 to 20, C atoms that is    optionally fluorinated,-   b) the group consisting of linear or branched alkylcarbonyl or    alkylcarbonyloxy with 2 to 30, preferably 2 to 20, C atoms, that is    optionally fluorinated.

In the formulae P1-P34, preferably R¹⁷ and R¹⁸, when being differentfrom H, are selected from the following groups:

-   a) the group consisting of linear or branched alkyl, alkoxy or    sulfanylalkyl with 1 to 30, preferably 1 to 20, C atoms that is    optionally fluorinated,-   b) the group consisting of linear or branched alkylcarbonyl or    alkylcarbonyloxy with 2 to 30, preferably 2 to 20, C atoms, that is    optionally fluorinated.-   c) the group consisting of F and C₁.

Further preferred are conjugated polymers selected of formula PT

R³¹-chain-R³²  PT

wherein “chain” denotes a polymer chain selected of formula Pi-viii orP1-P34, and R³¹ and R³² have independently of each other one of themeanings of R¹¹ as defined above, or denote, independently of eachother, H, F, Br, Cl, I, —CH₂Cl, —CHO, —CR′═CR″2, —SiR′R″R″′, —SiR′X′X″,—SiR′R″X′, —SnR′R″R″′, —BR′R″, —B(OR′)(OR″), —B(OH)₂, —O—SO₂—R′, —C≡CH,—C≡C—SiR′₃, —ZnX′ or an endcap group, X′ and X″ denote halogen, R′, R″and R″′ have independently of each other one of the meanings of R⁰ givenin formula 1, and preferably denote alkyl with 1 to 24 C atoms, and twoof R′, R″ and R″′ may also form a cyclosilyl, cyclostannyl, cycloboraneor cycloboronate group with 2 to 20 C atoms together with the respectivehetero atom to which they are attached.

Preferred endcap groups R³¹ and R³² are H, C₁₋₂₀ alkyl, or optionallysubstituted C₆₋₁₂ aryl or C₂₋₁₀ heteroaryl, very preferably H, phenyl orthiophene.

Another preferred embodiment of the present invention relates to a smallmolecule or oligomer comprising one or more units of formula I.Preferably the small molecule or oligomer according to this preferredembodiment is selected from formulae S1 and S2

R^(T1)—(Ar¹¹)_(a1)—[(Ar¹³)_(c1)—U—(Ar¹⁴)_(d1)-]_(e1)(Ar¹²)_(b1)—R^(T2)  S1

R^(T1)—(Ar²¹)_(a2)—(Ar²³)_(c2)-[(core1)_(f2)—(Ar²⁵)_(e2)-(core2)_(g2)]_(h2)—(Ar²⁴)_(d2)—(Ar²²)_(b2)—R^(T2)  S2

wherein the individual radicals, independently of each other and on eachoccurrence identically or differently, have the following meanings

-   U a unit of formula I or its subformulae,-   Ar¹¹⁻¹⁴ arylene or heteroarylene that has from 5 to 20 ring atoms,    is mono- or polycyclic, optionally contains fused rings, and is    unsubstituted or substituted by one or more identical or different    groups R¹, or —CY¹═CY²— or —C≡C—,-   Ar²¹⁻²⁵ arylene or heteroarylene that has from 5 to 20 ring atoms,    is mono- or polycyclic, optionally contains fused rings, and is    unsubstituted or substituted by one or more identical or different    groups R¹, or —CY¹═CY²— or —C≡C—,    wherein at least one of Ar²¹⁻²⁵, preferably at least one of Ar²¹⁻²⁴,    denotes U,-   core1, core2 polycyclic, fused arylene or heteroarylene that has    from 8 to 30 ring atoms, and is unsubstituted or substituted by one    or more identical or different groups R¹,-   R¹H, F, Cl, CN, or straight-chain, branched or cyclic alkyl with 1    to 30, preferably 1 to 20, C atoms, in which one or more CH₂ groups    are optionally replaced by —O—, —S—, —C(═O)—, —C(═S)—, —C(═O)—O—,    —O—C(═O)—, —NR⁰—, —SiR⁰R⁰⁰—, —CF₂—, —CR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C—    in such a manner that O and/or S atoms are not linked directly to    one another, and in which one or more H atoms are optionally    replaced by F, Cl, Br, I or CN, and in which one or more CH₂ or CH₃    groups are optionally replaced by a cationic or anionic group, or    aryl, heteroaryl, arylalkyl, heteroarylalkyl, aryloxy or    heteroaryloxy, wherein each of the aforementioned cyclic groups has    5 to 20 ring atoms, is mono- or polycyclic, does optionally contain    fused rings, and is unsubstituted or substituted by one or more    identical or different groups L as defined above,-   Y¹, Y²H, F, Cl or CN,-   R⁰, R⁰⁰H or linear or branched alkyl with 1 to 20, preferably 1 to    12, C atoms that is optionally fluorinated,-   R^(T1), R^(T2) H, F, Cl, Br, —NO₂, or a carbyl or hydrocarbyl group    with 1 to 30 C atoms that is optionally substituted by one or more    groups L and optionally comprises one or more hetero atoms,    -   and wherein in formula S2 preferably at least one of R^(T1) and        R^(T2) is H or an electron withdrawing group,-   a1-d1 0, 1, 2 or 3, preferably with at least one of a1-d1 being ≥1,-   e1 1, 2 or 3,-   a2-e2 0, 1, 2 or 3, with at least one of a2, b2, c2 and d2 being ≥1,-   f2 1, 2 or 3,-   g2 0, 1, 2 or 3,-   h2 1, 2 or 3.

In a preferred embodiment of the present invention the groups R^(T1) andR^(T2) in formula S1 are selected from alkyl with 1 to 16 C atoms whichis linear, branched or cyclic, and is unsubstituted, substituted withone or more F or C₁ atoms or CN groups, or perfluorinated, and in whichone or more C atoms are optionally replaced by —O—, —S—, —C(O)—, —C(S)—,—SiR⁰R⁰⁰—, —NR⁰R⁰⁰—, —CHR⁰═CR⁰⁰— or —C≡C— such that O- and/or S-atomsare not directly linked to each other.

In another preferred embodiment of the present invention at least one,preferably both of the groups R^(T1) and R^(T2) in formula S1 and S2denote electron withdrawing groups.

Preferably the groups R^(T1) and R^(T2) in formula S1 and S2 are eachindependently selected from H, F, C, Br, —NO₂, —CN, —CF₃, R*, —CF₂—R*,—O—R*, —S—R*, —SO₂—R*, —SO₃—R*, —C(═O)—H, —C(═O)—R*, —C(═S)—R*,—C(═O)—CF₂—R*, —C(═O)—OR*, —C(═S)—OR*, —O—C(═O)—R*, —O—C(═S)—R*,—C(═O)—SR*, —S—C(═O)—R*, —C(═O)NR*R**, —NR*—C(═O)—R*, —NHR*, —NR*R**,—CR*═CR*R**, —C≡C—R*, —C≡C—SiR*R**R***, —SiR*R**R***, —CH═CH(CN),—CH═C(CN)₂, —C(CN)═C(CN)₂, —CH═C(CN)(R^(a)), CH═C(CN)—C(═O)—OR*,—CH═C(CO—OR*)₂, —CH═C(CO—NR*R**)₂, and the group consisting of thefollowing formulae

wherein the individual radicals, independently of each other and on eachoccurrence identically or differently, have the following meanings

-   R^(a), R^(b) aryl or heteroaryl, each having from 4 to 30,    preferably from 5 to 20, ring atoms, optionally containing fused    rings and being unsubstituted or substituted with one or more groups    L, or one of the meanings given for L,-   R*, R**, R*** alkyl with 1 to 20 C atoms which is straight-chain,    branched or cyclic, and is unsubstituted, or substituted with one or    more F or Cl atoms or CN groups, or perfluorinated, and in which one    or more C atoms are optionally replaced by —O—, —S—, —C(═O)—,    —C(═S)—, —SiR⁰R⁰⁰—, —NR⁰R⁰⁰—, —CHR⁰═CR⁰⁰— or —C≡C— such that O-    and/or S-atoms are not directly linked to each other,-   L F, Cl, —NO₂, —CN, —NC, —NCO, —NCS, —OCN, —SCN, R⁰, OR⁰, SR⁰,    —C(═O)X⁰, —C(═O)R⁰, —C(═O)—OR⁰, —O—C(═O)—R⁰, —NH₂, —NHR⁰, —NR⁰R⁰⁰,    —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰, —SO₃R⁰, —SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, or    optionally substituted silyl, or carbyl or hydrocarbyl with 1 to 30,    preferably 1 to 20 C atoms that is optionally substituted and    optionally comprises one or more hetero atoms, preferably F, —CN,    R⁰, —OR⁰, —SR⁰, —C(═O)—R⁰, —C(═O)—OR⁰, —O—C(═O)—R⁰, —O—C(═O)—OR⁰,    —C(═O)—NHR⁰, —C(═O)—NR⁰R⁰⁰,-   L′ H or one of the meanings of L,-   R⁰, R⁰⁰H or straight-chain or branched alkyl with 1 to 20,    preferably 1 to 12 C atoms that is optionally fluorinated,-   Y¹, Y²H, F, C or CN,-   X⁰ halogen, preferably F or C,-   r 0, 1, 2, 3 or 4,-   s 0, 1, 2, 3, 4 or 5,-   t 0, 1, 2 or 3,-   u 0, 1 or 2,    and wherein preferably at least one of R^(T1) and R^(T2) denotes H    or an electron withdrawing group.

Preferred compounds of formula S1 and S2 are those wherein both ofR^(T1) and R^(T2) denote an electron withdrawing group.

Further preferred compounds of formula S1 and S2 are those wherein bothof R^(T1) and R^(T2) denote H.

Preferred electron withdrawing groups R^(T1) and R^(T2) are eachindependently selected from —CN, —C(═O)—OR*, —C(═S)—OR*, —CH═CH(CN),—CH═C(CN)₂, —C(CN)═C(CN)₂, —CH═C(CN)(R^(a)), CH═C(CN)—C(═O)—OR*,—CH═C(CO—OR*)₂, and formulae T1-T60.

Very preferred electron withdrawing groups R^(T1) and R^(T2) are eachindependently selected from the following formulae

wherein L, L′, R^(a), r and s have the meanings given above and below,and L′ is H or has one of the meanings given for L. Preferably in theseformulae L′ is H. Further preferably in these formulae r is 0.

The above formulae T1-T60 are meant to also include their respective E-or Z-stereoisomer with respect to the C═C bond in α-position to theadjacent group, thus for example the group

may also denote

Preferred compounds of formula S1 are those wherein Ar¹⁻⁸ are selectedfrom the following groups

-   a) the group consisting of the formulae D1-D151, very preferably of    the formulae D1, D7, D10, D11, D19, D22, D29, D30, D35, D36, D37,    D44, D55, D84, D87, D88, D89, D93, D94, D106, D111, D139, D140,    D141, D146 and D150,-   b) the group consisting of the formulae A1-A103, very preferably of    the formulae A1, A6, A7, A15, A16, A20, A36, A74, A84, A88, A92,    A94, A98 and A103,-   c) the group consisting of the formulae Sp1-Sp18, very preferably of    the formulae Sp1, Sp2, Sp6, Sp10, Sp11, Sp12, Sp13 and Sp14.

Further preferred compounds of formula S1 are selected from thefollowing preferred embodiments, including any combination thereof:

-   -   e1 is 1,    -   a1, b1 are 0, 1 or 2, and c1, d1 are 0,    -   a1+c1 is 1 or 2, and d1+b1 is 1 or 2,    -   Ar¹¹⁻¹⁴ are selected from formulae Sp1, Sp2, Sp6, Sp10, Sp11,        Sp12, Sp13 and Sp14,    -   R^(T1) and R^(T2) are selected from formulae T10, T36, T37, T38,        T39, T47 and T52.

Preferred compounds of formula S2 are those wherein those of Ar²¹⁻²⁵that are not a unit of formula I are each independently and on eachoccurrence identically or differently selected from the followingformulae and their mirror images:

wherein X²¹, X²², X²³ and X²⁴ denote H, F, Cl, —CN, R⁰, OR⁰ or C(═O)OR⁰,and R⁰ is as defined above and below, and wherein in formula AR6 thosegroups are excluded wherein one of X²¹ and X²² is F and the other of X²¹and X²² is C₁.

Further preferred compounds of formula S2 are those wherein core1 andcore2 are independently of each other, and on each occurrenceidentically or differently, selected from the following subformulae

wherein R¹ has the meaning given in formula S2, and R²⁻¹⁰, independentlyof each other and on each occurrence identically or differently, haveone of the meanings given for R¹, and the pair of R¹ and R², and/or thepair of R³ and R⁴, together with the C atom to which they are attached,may also form a spiro group with 5 to 20 ring atoms which is mono- orpolycyclic, optionally contains fused rings, and is unsubstituted orsubstituted by one or more identical or different groups L.

Very preferred compounds of formula S2 are selected of the followingformula

R^(T1)—(Ar²¹)_(a2)-core1-(Ar²²)_(b2)—R^(T2)  S2A

wherein R^(T1), R^(T2), core1, Ar²¹, Ar²², a2 and b2 are as defined informula S2, and “core1” is preferably selected from formulae C1-C26 asdefined above.

Further preferred compounds of formula S2 and S2A are selected from thefollowing groups:

1) The group consisting of compounds of formula S2 and S2A, whereincore1 is selected from formulae C1-C26, Ar²¹ and Ar²² are eachindependently a unit of formula I, a2 and b2 are each independently 1 or2, and R^(T1) and R^(T2) are selected from formula T10.2) The group consisting of compounds of formula S2 and S2A, whereincore1 is selected from formulae C1-C26, Ar²¹ and Ar²² are eachindependently a unit of formula I, a2 and b2 are each independently 1 or2, and R^(T1) and R^(T2) are selected from formula T36.3) The group consisting of compounds of formula S2 and S2A, whereincore1 is selected from formulae C1-C26, Ar²¹ and Ar²² are eachindependently a unit of formula I, a2 and b2 are each independently 1 or2, and R^(T1) and R^(T2) are selected from formula T37.4) The group consisting of compounds of formula S2 and S2A, whereincore1 is selected from formulae C1-C26, Ar²¹ and Ar²² are eachindependently a unit of formula I, a2 and b2 are each independently 1 or2, and R^(T1) and R^(T2) are selected from formula T38.5) The group consisting of compounds of formula S2 and S2A, whereincore1 is selected from formulae C1-C26, Ar²¹ and Ar²² are eachindependently a unit of formula I, a2 and b2 are each independently 1 or2, and R^(T1) and R^(T2) are selected from formula T39.6) The group consisting of compounds of formula S2 and S2A, whereincore1 is selected from formulae C1-C26, Ar²¹ and Ar²² are eachindependently a unit of formula I, a2 and b2 are each independently 1 or2, and R^(T1) and R^(T2) are selected from formula T47.7) The group consisting of compounds of formula S2 and S2A, whereincore1 is selected from formulae C1-C26, Ar²¹ and Ar²² are eachindependently a unit of formula I, a2 and b2 are each independently 1 or2, and R^(T1) and R^(T2) are selected from formula T52.8) The group consisting of compounds of formula S2 and S2A, whereincore1 is selected from formulae C1-C26, Ar²¹ and Ar²² are eachindependently a unit of formula I, a2 and b2 are each independently 1 or2, and R^(T1) and R^(T2) denote H.

In formula C1-C26 preferably one or both of R¹ and R² are different fromH, and one or both of R³ and R⁴ are different from H.

In a preferred embodiment, R¹⁻⁴ in formula C1-C26, when different fromH, are each independently selected from F, Cl or straight-chain orbranched alkyl, alkoxy, sulfanylalkyl, sulfonylalkyl, alkylcarbonyl,alkoxycarbonyl and alkylcarbonyloxy, very preferably alkyl or alkoxy,each having 1 to 20 C atoms and being unsubstituted or substituted byone or more F atoms, most preferably from formulae SUB1-SUB6 above.

In another preferred embodiment, R¹⁻⁴ in formula C1-C26, when differentfrom H, are each independently selected from mono- or polycyclic aryl orheteroaryl, each of which is optionally substituted with one or moregroups L as defined in formula I and has 5 to 20 ring atoms, and whereintwo or more rings may be fused to each other or connected with eachother by a covalent bond, very preferably from phenyl that is optionallysubstituted, preferably in 4-position, 3-position, 2,4-positions,3,5-positions, 2,6-positions, 3,4,5-positions or 2,4,6-positions, orfrom thiophene-2-yl that is optionally substituted, preferably in5-position, 4,5-positions, 3,5-positions, 3,4-positions or3,4,5-positions, with alkyl, alkoxy or thioalkyl having 1 to 16 C atoms,most preferably from formulae SUB7-SUB18 above.

In a preferred embodiment of the present invention, R⁵⁻¹⁰ in formulaC1-C26 are H.

In another preferred embodiment of the present invention, at least oneof R⁵⁻¹⁰ in formula C1-C26 is different from H.

In a preferred embodiment of the present invention, R⁵⁻¹⁰ in formulaC1-C26, when different from H, are each independently selected from F,Cl or straight-chain or branched alkyl, alkoxy, sulfanylalkyl,sulfonylalkyl, alkylcarbonyl, alkoxycarbonyl and alkylcarbonyloxy, eachhaving 1 to 20 C atoms and being unsubstituted or substituted by one ormore F atoms.

In another preferred embodiment of the present invention, R⁵⁻¹⁰ informula C1-C26, when different from H, are each independently selectedfrom aryl or heteroaryl, each of which is optionally substituted withone or more groups L as defined in formula I and has 5 to 20 ring atoms,and wherein two or more rings may be fused to each other or connectedwith each other by a covalent bond, very preferably from phenyl that isoptionally substituted, preferably in 4-position, 3-position,2,4-positions, 3,5-positions, 2,6-positions, 3,4,5-positions or2,4,6-positions, or from thiophene-2-yl that is optionally substituted,preferably in 5-position, 4,5-positions, 3,5-positions, 3,4-positions or3,4,5-positions, with alkyl, alkoxy or thioalkyl having 1 to 16 C atoms,most preferably from formulae SUB7-SUB18 above.

Further preferred compounds of formula S2 and S2A are selected from thefollowing preferred embodiments or any combination thereof:

-   -   e2, g2 and h2 are 0,    -   f2 is 1,    -   a2=c2=1 and b2=d2=0,    -   Ar²¹ and Ar²² are a unit of formula I,    -   those of Ar²¹⁻²⁵ that are not a unit of formula I are selected        from thiophene, thiazole, thieno[3,2-b]thiophene,        thiazolo[5,4-d]thiazole, benzene, 1,2,3-benzothiadiazole,        thieno[3,4-b]thiophene, benzotriazole or        thiadiazole[3,4-c]pyridine, which are substituted by X¹, X², X³        and X⁴ as defined above,    -   one or both of R¹ and R² and one or both of R³ and R⁴ are        different from H,    -   R¹, R², R³ and R⁴, when being different from H, are each        independently selected from H, F, Cl or straight-chain or        branched alkyl, alkoxy, sulfanylalkyl, sulfonylalkyl,        alkylcarbonyl, alkoxycarbonyl and alkylcarbonyloxy, each having        1 to 20 C atoms and being unsubstituted or substituted by one or        more F atoms, without being perfluorinated, or alkyl or alkoxy        having 1 to 12 C atoms that is optionally fluorinated,    -   R¹, R², R³ and R⁴, when being different from H, are each        independently selected from aryl or heteroaryl, each of which is        optionally substituted with one or more groups L as defined in        formula I and has 4 to 30 ring atoms, preferably from phenyl        that is optionally substituted, preferably in 4-position, or in        2,4-positions, or in 2,4,6-positions or in 3,5-positions, with        alkyl or alkoxy having 1 to 20 C atoms, preferably 1 to 16 C        atoms, very preferably from 4-alkylphenyl wherein alkyl is C1-16        alkyl, most preferably 4-methylphenyl, 4-hexylphenyl,        4-octylphenyl or 4-dodecylphenyl, or from 4-alkoxyphenyl wherein        alkoxy is C1-16 alkoxy, most preferably 4-hexyloxyphenyl,        4-octyloxyphenyl or 4-dodecyloxyphenyl, or from        2,4-dialkylphenyl wherein alkyl is C1-16 alkyl, most preferably        2,4-dihexylphenyl or 2,4-dioctylphenyl, or from        2,4-dialkoxyphenyl wherein alkoxy is C1-16 alkoxy, most        preferably 2,4-dihexyloxyphenyl or 2,4-dioctyloxyphenyl, or from        3,5-dialkylphenyl wherein alkyl is C1-16 alkyl, most preferably        3,5-dihexylphenyl or 3,5-dioctylphenyl, or from        3,5-dialkoxyphenyl wherein alkoxy is C1-16 alkoxy, most        preferably 3,5-dihexyloxyphenyl or 3,5-dioctyloxyphenyl, or from        2,4,6-trialkylphenyl wherein alkyl is C1-16 alkyl, most        preferably 2,4,6-trihexylphenyl or 2,4,6-trioctylphenyl, or from        2,4,6-trialkoxyphenyl wherein alkoxy is C1-16 alkoxy, most        preferably 2,4,6-trihexyloxyphenyl or 2,4,6-trioctyloxyphenyl,        or from 4-thioalkylphenyl wherein thioalkyl is C1-16 thioalkyl,        most preferably 4-thiohexylphenyl, 4-thiooctylphenyl or        4-thiododecylphenyl, or from 2,4-dithioalkylphenyl wherein        thioalkyl is C1-16 thioalkyl, most preferably        2,4-dithiohexylphenyl or 2,4-dithiooctylphenyl, or from        3,5-dithioalkylphenyl wherein thioalkyl is C1-16 thioalkyl, most        preferably 3,5-dithiohexylphenyl or 3,5-dithiooctylphenyl, or        from 2,4,6-trithioalkylphenyl wherein thioalkyl is C1-16        thioalkyl, most preferably 2,4,6-trithiohexylphenyl or        2,4,6-trithiooctylphenyl,    -   L′ is H,    -   L, L′ denote F, Cl, CN, NO₂, or alkyl or alkoxy with 1 to 16 C        atoms that is optionally fluorinated,    -   r is 1 and L is F, Cl, CN, NO₂, or alkyl or alkoxy with 1 to 16        C atoms that is optionally fluorinated,    -   r is 2 and L is F, Cl, CN, NO₂, or alkyl or alkoxy with 1 to 16        C atoms that is optionally fluorinated,    -   r is 4 and L is F, Cl, CN, NO₂, or alkyl or alkoxy with 1 to 16        C atoms that is optionally fluorinated,    -   R⁵⁻¹⁰, when being different from H, are each independently        selected from F, Cl or straight-chain or branched alkyl, alkoxy,        sulfanylalkyl, sulfonylalkyl, alkylcarbonyl, alkoxycarbonyl and        alkylcarbonyloxy, each having up to 20 C atoms and being        unsubstituted or substituted by one or more F atoms, without        being perfluorinated, preferably from F, or alkyl or alkoxy        having up to 16 C atoms that is optionally fluorinated.

Another preferred embodiment of the present invention relates to amonomer comprising one or more units of formula I and at least tworeactive groups that can be reacted to form a small molecule, oligomeror conjugated polymer as described above and below, preferably in anaryl-aryl coupling reaction. Preferably the monomer according to thispreferred embodiment is a compound of formula M1 or M2

R²³—(Ar¹)_(a)—U—(Ar²)_(b)—(Ar³)_(c)—(Ar⁴)_(d)—R²⁴  M1

R²³—(Ar¹)_(a)—(Ar²)_(b)—U—(Ar³)_(c)—(Ar⁴)_(d)—R²⁴  M2

wherein U, Ar¹⁻⁴, a, b, c and d have the meanings of formula II, or oneof the preferred meanings as described above and below, and R²³ and R²⁴are independently of each other selected from the group consisting of anactivated C—H bond, Cl, Br, I, O-tosylate, O-triflate, O-mesylate,O-nonaflate, —SiMe₂F, —SiMeF₂, —O—SO₂Z¹, —B(OZ²)₂, —CZ³═C(Z³)₂, —C≡CH,—C≡CSi(Z¹)₃, —ZnX⁰ and —Sn(Z⁴)₃, wherein X⁰ is halogen, Z¹⁻⁴ areselected from the group consisting of alkyl and aryl, preferably C₁₋₁₀alkyl and C₆₋₁₂ aryl, each being optionally substituted, and two groupsZ² may also form a cycloboronate group having 2 to 20 C atoms togetherwith the B- and O-atoms.

Preferably in the monomers of formula M1 and M2 Ar¹⁻⁴ are selected fromthe group consisting of formulae D1-D151, A1-A103 and Sp1-Sp18, verypreferably from formulae Sp1-Sp18, most preferably from formulae Sp1,Sp6, Sp10 and Sp14.

Very preferred are monomers of formula M1 and M2 and their subformulaewherein a+b+c+d≥1.

Further preferred are monomers of formula M1 and its subformulae whereina+b+c+d=0.

Very preferred are monomers of of formulae M1 and M2 wherein Ar¹⁴,independently of each other and on each occurrence identically ordifferently, are selected from the following groups

-   a) the group consisting of the formulae D1-D151, very preferably of    the formulae D1, D7, D10, D11, D19, D22, D29, D30, D35, D36, D37,    D44, D55, D84, D87, D88, D89, D93, D94, D106, D111, D139, D140, D141    and D150,-   b) the group consisting of the formulae A1-A103, very preferably of    the formulae A1, A6, A7, A15, A16, A20, A36, A74, A84, A88, A92, A98    and A103,-   c) the group consisting of the formulae Sp1-Sp18, very preferably of    the formulae Sp1, Sp2, Sp6, Sp10, Sp11, Sp12, Sp13 and Sp14.

Further preferred are monomers selected from the following subformulae

R²³—U—R²⁴  M1a

R²³—Sp-U-Sp-R²⁴  M1 b

R²³-Sp-U—R²⁴  M1c

R²³—U-D-R²⁴  M1d

wherein U, R²³ and R²⁴ are as defined in formula M1, and Sp and D are asdefined in formula U1-U7 or have one of the preferred meanings givenabove and below.

Very preferred are monomers of formulae M1a-M1d wherein

-   a) one or more, preferably all, groups D are selected from the group    consisting of the formulae D1-D151, very preferably of the formulae    D1, D7, D10, D11, D19, D22, D29, D30, D35, D36, D37, D44, D55, D84,    D87, D88, D89, D93, D94, D106, D111, D119, D139, D140, D141, D146,    D147 and D150, and/or-   b) one or more, preferably all, groups Sp are selected from the    group consisting of the formulae Sp1-Sp18, very preferably of the    formulae Sp1, Sp2, Sp6, Sp10, Sp11, Sp12, Sp13 and Sp14.

Further preferred are monomers of the following subformulae:

wherein R¹¹, R¹², R¹³, R¹⁴, R²³ and R²⁴ have the meanings given aboveand below.

Very preferred are monomers of formula M1a1 and M1b1.

Further preferred are monomers of formulae M1b1-M1b3 wherein all groupsR¹¹⁻¹⁴ are H.

Further preferred are monomers of formulae M1b1-M1b3 wherein at leastone of the groups R¹¹⁻¹⁴ is different from H, and is preferably selectedfrom F, Cl, or linear or branched alkyl, alkoxy or thiaalkyl with 1 to30, preferably 1 to 24 C atoms that is optionally fluorinated.

Further preferred are monomers of formulae M1b1-M1b3 wherein thethiophene groups are asymmetrically substituted by R¹¹⁻¹⁴, for example

-   -   only one of R¹¹⁻¹⁴ is H and the others are different from H,    -   only one of R¹¹⁻¹⁴ is different from H and the others are H,    -   R¹¹ and R¹³ are H and R¹² and R¹⁴ are different from H,    -   R¹¹ and R¹³ are different from H and R¹² and R¹⁴ are H,        and wherein those substituents R¹¹⁻¹⁴ that are different from H        are selected from F, Cl, or linear or branched alkyl, alkoxy or        thiaalkyl with 1 to 30, preferably 1 to 24 C atoms that is        optionally fluorinated.

Further preferred are monomers of formulae M1a3 and M1b3 wherein R isselected from the group consisting of H and linear or branched alkylwith 1 to 20, preferably 1 to 12 C atoms that is optionally fluorinated.

Further preferred are monomers of formula M1, M2, M1a-M1d and theirsubformulae wherein R²³ and R²⁴ are selected from Br, Cl, B(OZ²)₂ andSn(Z⁴)₃.

The monomers, small molecules, oligomers and polymers according to thepresent invention can be synthesized according to or in analogy tomethods that are known to the skilled person and are described in theliterature. Other methods of preparation can be taken from the examples.

The conjugated polymers according to the present invention can beprepared for example by copolymerising one or more monomers of formulaM1, M2 or M1a-M1d with each other or with one or monomers of thefollowing formulae in an aryl-aryl coupling reaction

R²³-Sp-R²⁴  MI

R²³-A-R²⁴  MII

R²³-D-R²⁴  MIII

R²³-Sp-A-R²⁴  MIV

R²³-Sp-D-R²⁴  MV

R²³-Sp-A-Sp-R²⁴  MVI

R²³-Sp-D-Sp-R²⁴  MVII

wherein Sp, A and D, independently of each other and on each occurrenceidentically or differently, have one of the meanings given in formulaU1-U7 or one of the preferred meanings given above and below, and R²³and R²⁴ have the meanings given in formula M1 or one of the preferredmeanings given above and below.

For example, the conjugated polymer can be suitably prepared byaryl-aryl coupling reactions, such as Yamamoto coupling, C—H activationcoupling, Suzuki coupling, Stille coupling, Sonogashira coupling, Heckcoupling or Buchwald coupling. Suzuki coupling, Stille coupling andYamamoto coupling are especially preferred. The monomers which arepolymerised to form the repeat units of the polymers can be preparedaccording to methods which are known to the person skilled in the art.

Preferably the polymer is prepared from monomers selected from formulaeM1, M2, M3, M1a-d and MI-MVII as described above.

Another aspect of the invention is a process for preparing a polymer bycoupling one or more identical or different monomers selected fromformulae M1, M2, M1a-d with each other and/or with one or moreco-monomers, preferably selected from formulae MI-MVII, in apolymerisation reaction, preferably in an aryl-aryl coupling reaction.

The small molecules, monomers, oligomers and polymers of the presentinvention can generally be prepared by aryl-aryl coupling reactions,such as Yamamoto coupling, Suzuki coupling, Stille coupling, Sonogashiracoupling, Heck coupling or Buchwald coupling. The educts can be preparedaccording to methods which are known to the person skilled in the art.

Preferred aryl-aryl coupling methods used in the synthesis methods asdescribed above and below are Yamamoto coupling, Kumada coupling,Negishi coupling, Suzuki coupling, Stille coupling, Sonogashiracoupling, Heck coupling, C—H activation coupling, Ullmann coupling orBuchwald coupling. Especially preferred are Suzuki coupling, Negishicoupling, Stille coupling and Yamamoto coupling. Suzuki coupling isdescribed for example in WO 00/53656 A1. Negishi coupling is describedfor example in E. Nigishi et al., J. Chem. Soc., Chem. Commun., 1977,683-684. Yamamoto coupling is described in for example in T. Yamamoto etal., Prog. Polym. Sci., 1993, 17, 1153-1205, or WO 2004/022626 A1.Stille coupling is described for example in Z. Bao et al., J. Am. Chem.Soc., 1995, 117, 12426-12435 and C—H activation is described for examplein M. Leclerc et al., Angew. Chem. Int. Ed., 2012, 51, 2068-2071. Forexample, when using Yamamoto coupling, educts having two reactive halidegroups are preferably used. When using Suzuki coupling, educts havingtwo reactive boronic acid or boronic acid ester groups or two reactivehalide groups are preferably used. When using Stille coupling, edcutshaving two reactive stannane groups or two reactive halide groups arepreferably used. When using Negishi coupling, educts having two reactiveorganozinc groups or two reactive halide groups are preferably used.

Preferred catalysts, especially for Suzuki, Negishi or Stille coupling,are selected from Pd(0) complexes or Pd(II) salts. Preferred Pd(0)complexes are those bearing at least one phosphine ligand such asPd(PPh₃)₄. Another preferred phosphine ligand istris(ortho-tolyl)phosphine, i.e. Pd(P(o-Tol)₃)₄. Preferred Pd(II) saltsinclude palladium acetate, i.e. Pd(OAc)₂. Alternatively the Pd(0)complex can be prepared by mixing a Pd(0) dibenzylideneacetone complex,for example tris(dibenzyl-ideneacetone)dipalladium(0),bis(dibenzylideneacetone)palladium(0), or Pd(II) salts e.g. palladiumacetate, with a phosphine ligand, for example triphenylphosphine,tris(ortho-tolyl)phosphine or tri(tert-butyl)phosphine. Suzuki couplingis performed in the presence of a base, for example sodium carbonate,potassium carbonate, cesium carbonate, lithium hydroxide, potassiumphosphate or an organic base such as tetraethylammonium carbonate ortetraethylammonium hydroxide. Yamamoto coupling employs a Ni(0) complex,for example bis(1,5-cyclooctadienyl) nickel(0).

As alternatives to halogens as described above, leaving groups offormula —O—SO₂Z⁰ can be used wherein Z⁰ is an alkyl or aryl group,preferably C₁₋₁₀ alkyl or C₆₋₁₂ aryl. Particular examples of suchleaving groups are tosylate, mesylate and triflate.

Especially suitable and preferred synthesis methods of the compounds offormula I and its subformulae are illustrated in the synthesis schemesshown hereinafter.

The synthesis of preferred monomers of formula M1a and M1b isexemplarily shown in Scheme 1.

The synthesis of alternating co-polymers with a unit of formula I isexemplarily shown in Scheme 2. Therein R²³=Br and R²⁴=SnR₃; or R²³=Brand R²⁴=B(OR)₂; or R²³=SnR₃ and R²⁴=Br; or R²³=B(OR)₂ and R²⁴=Br; orR²³=Br or Cl, or R²³=H and R²⁴=Br, Cl or I, or R²⁴=H and R²³=Br, Cl orI, Ar¹⁻⁴ is optionally substituted arylene or heteroarylene as definedfor A, for example thiophene, benzene, furane or pyridine, Sp and D informula Pi-iv, and a-d are 0 or 1 with a+b+c+d≥0, R is for examplealkyl, n is an integer>1, and X¹ and X² are as defined in formula I.

The synthesis of statistical co-polymers with a unit of formula I isexemplarily shown in Scheme 3, wherein the individual radicals are asdefined in Scheme 2, and m has one of the meanings of n.

The synthesis of oliogomers and small molecules with a unit of formula Iis exemplarily shown in Scheme 4. Alternatively these compounds can beobtained via a convergent synthesis strategy as exemplarily shown inScheme 5. Therein the individual radicals are as defined in Scheme 2,Ar⁵⁻⁸ have of the meanings given for Ar¹⁻⁴, e-h have of the meaningsgiven for a-d, and R^(T1) and R^(T2) have the meanings given in formulaS.

Novel methods of preparing compounds comprising a unit of formula I asdescribed above and below are another aspect of the invention.

The compounds according to the present invention can also be used incompositions, for example together with monomeric or polymeric compoundshaving charge-transport, semiconducting, electrically conducting,photoconducting and/or light emitting semiconducting properties, or forexample with compounds having hole blocking or electron blockingproperties for use as interlayers or charge blocking layers in PSCs orOLEDs.

Thus, another aspect of the invention relates to a compositioncomprising one or more compounds according to the present invention andone or more small molecule compounds and/or polymers having one or moreof a charge-transport, semiconducting, electrically conducting,photoconducting, hole blocking and electron blocking property.

These compositions blends can be prepared by conventional methods thatare described in prior art and known to the skilled person. Typicallythe compounds and/or polymers are mixed with each other or dissolved insuitable solvents and the solutions combined.

Another aspect of the invention relates to a formulation comprising oneor more compounds according to the present invention or compositions asdescribed above and below and one or more organic solvents.

Preferred solvents are aliphatic hydrocarbons, chlorinated hydrocarbons,aromatic hydrocarbons, ketones, ethers and mixtures thereof. Additionalsolvents which can be used include 1,2,4-trimethylbenzene,1,2,3,4-tetra-methyl benzene, pentylbenzene, mesitylene, cumene, cymene,cyclohexylbenzene, diethylbenzene, tetralin, decalin, 2,6-lutidine,2-fluoro-m-xylene, 3-fluoro-o-xylene, 2-chlorobenzotrifluoride,N,N-dimethylformamide, 2-chloro-6-fluorotoluene, 2-fluoroanisole,anisole, 2,3-dimethylpyrazine, 4-fluoroanisole, 3-fluoroanisole,3-trifluoro-methylanisole, 2-methylanisole, phenetol, 4-methylanisole,3-methylanisole, 4-fluoro-3-methylanisole, 2-fluorobenzonitrile,4-fluoroveratrol, 2,6-dimethylanisole, 3-fluorobenzo-nitrile,2,5-dimethylanisole, 2,4-dimethylanisole, benzonitrile,3,5-dimethyl-anisole, N,N-dimethylaniline, ethyl benzoate,1-fluoro-3,5-dimethoxy-benzene, 1-methylnaphthalene,N-methylpyrrolidinone, 3-fluorobenzo-trifluoride, benzotrifluoride,dioxane, trifluoromethoxy-benzene, 4-fluorobenzotrifluoride,3-fluoropyridine, toluene, 2-fluoro-toluene, 2-fluorobenzotrifluoride,3-fluorotoluene, 4-isopropylbiphenyl, phenyl ether, pyridine,4-fluorotoluene, 2,5-difluorotoluene, 1-chloro-2,4-difluorobenzene,2-fluoropyridine, 3-chlorofluoro-benzene, 1-chloro-2,5-difluorobenzene,4-chlorofluorobenzene, chloro-benzene, o-dichlorobenzene,2-chlorofluorobenzene, p-xylene, m-xylene, o-xylene or mixture of o-,m-, and p-isomers. Solvents with relatively low polarity are generallypreferred. For inkjet printing solvents and solvent mixtures with highboiling temperatures are preferred. For spin coating alkylated benzeneslike xylene and toluene are preferred.

Examples of especially preferred solvents include, without limitation,dichloromethane, trichloromethane, chlorobenzene, o-dichlorobenzene,tetrahydrofuran, anisole, 2,4-dimethylanisole, 1-methylnaphthalene,morpholine, toluene, o-xylene, m-xylene, p-xylene, 1,4-dioxane, acetone,methylethylketone, 1,2-dichloroethane, 1,1,1-trichloroethane,1,1,2,2-tetrachloroethane, ethyl acetate, n-butyl acetate,N,N-dimethylformamide, dimethylacetamide, dimethylsulfoxide,1,5-dimethyltetraline, propiophenone, acetophenone, tetraline,2-methylthiophene, 3-methylthiophene, decaline, indane, methyl benzoate,ethyl benzoate, mesitylene and/or mixtures thereof.

The concentration of the compounds or polymers in the solution ispreferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight.Optionally, the solution also comprises one or more binders to adjustthe rheological properties, as described for example in WO 2005/055248A1.

After the appropriate mixing and ageing, solutions are evaluated as oneof the following categories: complete solution, borderline solution orinsoluble. The contour line is drawn to outline the solubilityparameter-hydrogen bonding limits dividing solubility and insolubility.‘Complete’ solvents falling within the solubility area can be chosenfrom literature values such as published in “Crowley, J. D., Teague, G.S. Jr and Lowe, J. W. Jr., Journal of Paint Technology, 1966, 38 (496),296”. Solvent blends may also be used and can be identified as describedin “Solvents, W. H. Ellis, Federation of Societies for CoatingsTechnology, p 9-10, 1986”. Such a procedure may lead to a blend of ‘non’solvents that will dissolve both the polymers of the present invention,although it is desirable to have at least one true solvent in a blend.

The compounds according to the present invention can also be used inpatterned OSC layers in the devices as described above and below. Forapplications in modern microelectronics it is generally desirable togenerate small structures or patterns to reduce cost (more devices/unitarea), and power consumption. Patterning of thin layers comprising acompound according to the present invention can be carried out forexample by photolithography, electron beam lithography or laserpatterning.

For use as thin layers in electronic or electrooptical devices thecompounds, compositions or formulations of the present invention may bedeposited by any suitable method. Liquid coating of devices is moredesirable than vacuum deposition techniques. Solution deposition methodsare especially preferred. The formulations of the present inventionenable the use of a number of liquid coating techniques. Preferreddeposition techniques include, without limitation, dip coating, spincoating, ink jet printing, nozzle printing, letter-press printing,screen printing, gravure printing, doctor blade coating, rollerprinting, reverse-roller printing, offset lithography printing, dryoffset lithography printing, flexographic printing, web printing, spraycoating, curtain coating, brush coating, slot dye coating or padprinting.

Ink jet printing is particularly preferred when high resolution layersand devices needs to be prepared. Selected formulations of the presentinvention may be applied to prefabricated device substrates by ink jetprinting or microdispensing. Preferably industrial piezoelectric printheads such as but not limited to those supplied by Aprion, Hitachi-Koki,InkJet Technology, On Target Technology, Picojet, Spectra, Trident, Xaarmay be used to apply the organic semiconductor layer to a substrate.Additionally semi-industrial heads such as those manufactured byBrother, Epson, Konica, Seiko Instruments Toshiba TEC or single nozzlemicrodispensers such as those produced by Microdrop and Microfab may beused.

In order to be applied by ink jet printing or microdispensing, thecompounds or polymers should be first dissolved in a suitable solvent.Solvents must fulfil the requirements stated above and must not have anydetrimental effect on the chosen print head. Additionally, solventsshould have boiling points>100° C., preferably >140° C. and morepreferably >150° C. in order to prevent operability problems caused bythe solution drying out inside the print head. Apart from the solventsmentioned above, suitable solvents include substituted andnon-substituted xylene derivatives, di-C₁₋₂-alkyl formamide, substitutedand non-substituted anisoles and other phenol-ether derivatives,substituted heterocycles such as substituted pyridines, pyrazines,pyrimidines, pyrrolidinones, substituted and non-substitutedN,N-di-C₁₋₂-alkylanilines and other fluorinated or chlorinatedaromatics.

A preferred solvent for depositing a compound according to the presentinvention by ink jet printing comprises a benzene derivative which has abenzene ring substituted by one or more substituents wherein the totalnumber of carbon atoms among the one or more substituents is at leastthree. For example, the benzene derivative may be substituted with apropyl group or three methyl groups, in either case there being at leastthree carbon atoms in total. Such a solvent enables an ink jet fluid tobe formed comprising the solvent with the compound or polymer, whichreduces or prevents clogging of the jets and separation of thecomponents during spraying. The solvent(s) may include those selectedfrom the following list of examples: dodecylbenzene,1-methyl-4-tert-butylbenzene, terpineol, limonene, isodurene,terpinolene, cymene, diethylbenzene. The solvent may be a solventmixture, that is a combination of two or more solvents, each solventpreferably having a boiling point>100° C., more preferably >140° C. Suchsolvent(s) also enhance fil m formation in the layer deposited andreduce defects in the layer.

The ink jet fluid (that is mixture of solvent, binder and semiconductingcompound) preferably has a viscosity at 20° C. of 1-100 mPa·s, morepreferably 1-50 mPa·s and most preferably 1-30 mPa·s.

The compositions and formulations according to the present invention canadditionally comprise one or more further components or additivesselected for example from surface-active compounds, lubricating agents,wetting agents, dispersing agents, hydrophobing agents, adhesive agents,flow improvers, defoaming agents, deaerators, diluents which may bereactive or non-reactive, auxiliaries, colourants, dyes or pigments,sensitizers, stabilizers, nanoparticles or inhibitors.

The compounds according to the present invention are useful as chargetransport, semiconducting, electrically conducting, photoconducting orlight emitting materials in optical, electrooptical, electronic,electroluminescent or photoluminescent components or devices. In thesedevices, the compounds of the present invention are typically applied asthin layers or films.

Thus, the present invention also provides the use of the semiconductingcompound or composition or layer in an electronic device. The compoundor composition may be used as a high mobility semiconducting material invarious devices and apparatus. The compound or composition may be used,for example, in the form of a semiconducting layer or film. Accordingly,in another aspect, the present invention provides a semiconducting layerfor use in an electronic device, the layer comprising a compound orcomposition according to the present invention. The layer or film may beless than about 30 microns. For various electronic device applications,the thickness may be less than about 1 micron thick. The layer may bedeposited, for example on a part of an electronic device, by any of theaforementioned solution coating or printing techniques.

The invention additionally provides an electronic device comprisingcompound or composition or organic semiconducting layer according to thepresent invention. Especially preferred devices are OFETs, TFTs, ICs,logic circuits, capacitors, RFID tags, OLEDs, OLETs, OPEDs, OPVs, PSCs,OPDs, solar cells, laser diodes, photoconductors, photodetectors,electrophotographic devices, electrophotographic recording devices,organic memory devices, sensor devices, charge injection layers,Schottky diodes, planarising layers, antistatic films, conductingsubstrates and conducting patterns.

Especially preferred electronic device are OFETs, OLEDs, OPV, PSC andOPD devices, in particular OPD, PSC and bulk heterojunction (BHJ) OPVdevices. In an OFET, for example, the active semiconductor channelbetween the drain and source may comprise the compound or composition ofthe invention. As another example, in an OLED device, the charge (holeor electron) injection or transport layer may comprise the compound orcomposition of the invention.

For use in the photoactive layer of OPV or OPD devices the compoundsaccording to the present invention are preferably used in a compositionthat comprises or contains, more preferably consists of, one or morep-type (electron donor) semiconductors and one or more n-type (electronacceptor) semiconductors.

The p-type semiconductor is for example constituted by a compound,preferably a conjugated polymer, according to the present invention, oranother conjugated polymer.

The n-type semiconductor for example constituted by a compound,preferably a small molecule, according to the present invention, or isfor example a fullerene or substituted fullerene.

The fullerene is for example an indene-C₆₀-fullerene bisadduct likeICBA, or a (6,6)-phenyl-butyric acid methyl ester derivatized methano Cofullerene, also known as “PCBM-C₆₀” or “C₆₀PCBM”, as disclosed forexample in G. Yu, J. Gao, J. C. Hummelen, F. Wudl, A. J. Heeger,Science, 1995, Vol. 270, p. 1789 ff and having the structure shownbelow, or structural analogous compounds with e.g. a C₆₁ fullerenegroup, a C₇₀ fullerene group, or a C₇₁ fullerene group, or an organicpolymer (see for example Coakley, K. M. and McGehee, M. D. Chem. Mater.,2004, 16, 4533).

Preferably the fullerene or substituted fullerene is selected fromformula Full-I

wherein

-   C_(n) denotes a fullerene composed of n carbon atoms, optionally    with one or more atoms trapped inside,-   Adduct¹ is a primary adduct appended to the fullerene C_(n) with any    connectivity,-   Adduct² is a secondary adduct, or a combination of secondary    adducts, appended to the fullerene C_(n) with any connectivity,-   k is an integer≥1,-   and-   I is 0, an integer≥1, or a non-integer>0.

In the formula Full-I and its subformulae, k preferably denotes 1, 2, 3or, 4, very preferably 1 or 2.

The fullerene C_(n) in formula Full-I and its subformulae may becomposed of any number n of carbon atoms Preferably, in the compounds offormula XII and its subformulae the number of carbon atoms n of whichthe fullerene C_(n) is composed is 60, 70, 76, 78, 82, 84, 90, 94 or 96,very preferably 60 or 70.

The fullerene C_(n) in formula Full-I and its subformulae is preferablyselected from carbon based fullerenes, endohedral fullerenes, ormixtures thereof, very preferably from carbon based fullerenes.

Suitable and preferred carbon based fullerenes include, withoutlimitation, (C_(60-Ih))[5,6]fullerene, (C_(70-D5h))[5,6]fullerene,(C_(76-D2) ₊ )[5,6]fullerene, (C_(84-D2) ₊ )[5,6]fullerene,(C_(84-D2d))[5,6]fullerene, or a mixture of two or more of theaforementioned carbon based fullerenes.

The endohedral fullerenes are preferably metallofullerenes. Suitable andpreferred metallofullerenes include, without limitation, La@C₆₀, La@C₈₂,Y@C₈₂, Sc₃N@C₈₀, Y₃N@C₈₀, Sc₃C₂@C₈₀ or a mixture of two or more of theaforementioned metallofullerenes.

Preferably the fullerene C_(n) is substituted at a [6,6] and/or [5,6]bond, preferably substituted on at least one [6,6] bond.

Primary and secondary adduct, named “Adduct” in formula Full-I and itssubformulae, is preferably selected from the following formulae

wherein

-   Ar^(S1), Ar^(S2) denote, independently of each other, an aryl or    heteroaryl group with 5 to 20, preferably 5 to 15, ring atoms, which    is mono- or polycyclic, and which is optionally substituted by one    or more identical or different substituents having one of the    meanings of L as defined above and below,    R^(S1), R^(S2), R^(S3), R^(S4) and R^(S5) independently of each    other denote H, CN or have one of the meanings of R^(S) as defined    above and below,    and i is an integer from 1 to 20, preferably from 1 to 12.

Preferred compounds of formula Full-I are selected from the followingsubformulae, wherein k and l are as defined in formula Full-I:

whereinR^(S1), R^(S2), R^(S3), R^(S4) R^(S5) and R^(S6) independently of eachother denote H or have one of the meanings of R^(S) as defined above andbelow.

Most preferably the fullerene is PCBM-C60, PCBM-C70, bis-PCBM-C60,bis-PCBM-C70, ICMA-c60(1′,4′-dihydro-naphtho[2′,3′:1,2][5,6]fullerene-C60), ICBA, oQDM-C60(1′,4′-dihydro-naphtho[2′,3′:1,9][5,6]fullerene-C60-Ih), orbis-oQDM-C60.

The OPV or OPD device preferably further comprises a first transparentor semi-transparent electrode on a transparent or semi-transparentsubstrate on one side of the photoactive layer, and a second metallic orsemi-transparent electrode on the other side of the photoactive layer.

Further preferably the OPV or OPD device comprises, between thephotoactive layer and the first or second electrode, one or moreadditional buffer layers acting as hole transporting layer and/orelectron blocking layer, which comprise a material such as metal oxide,like for example, ZTO, MoO_(x), NiO_(x), a conjugated polymerelectrolyte, like for example PEDOT:PSS, a conjugated polymer, like forexample polytriarylamine (PTAA), an insulating polymer, like for examplenafion, polyethyleneimine or polystyrenesulphonate, an organic compound,like for exampleN,N′-diphenyl-N,N′-bis(1-naphthyl)(1,1′-biphenyl)-4,4′diamine (NPB),N,N′-diphenyl-N,N′-(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine (TPD), oralternatively as hole blocking layer and/or electron transporting layer,which comprise a material such as metal oxide, like for example,ZnO_(x), TiO_(x), a salt, like for example LiF, NaF, CsF, a conjugatedpolymer electrolyte, like for examplepoly[3-(6-trimethylammoniumhexyl)thiophene],poly(9,9-bis(2-ethylhexyl)-fluorene]-b-poly[3-(6-trimethylammoniumhexyl)thiophene],or poly[(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)]or an organic compound, like for exampletris(8-quinolinolato)-aluminium(III) (Alq₃),4,7-diphenyl-1,10-phenanthroline.

In a composition according to the present invention comprising a p-typeOSC which is a conjugated polymer and an n-type OSC compound, the ratiopolymer:n-type OSC compound is preferably from 5:1 to 1:5 by weight,more preferably from 3:1 to 1:3 by weight, most preferably 2:1 to 1:2 byweight.

The composition according to the present invention may also comprise apolymeric binder, preferably from 0.001 to 95% by weight. Examples ofbinder include polystyrene (PS), polydimethylsilane (PDMS),polypropylene (PP) and polymethylmethacrylate (PMMA).

A binder to be used in the formulation as described before, which ispreferably a polymer, may comprise either an insulating binder or asemiconducting binder, or mixtures thereof, may be referred to herein asthe organic binder, the polymeric binder or simply the binder.Preferably, the polymeric binder comprises a weight average molecularweight in the range of 1000 to 5,000,000 g/mol, especially 1500 to1,000,000 g/mol and more preferable 2000 to 500,000 g/mol. Surprisingeffects can be achieved with polymers having a weight average molecularweight of at least 10000 g/mol, more preferably at least 100000 g/mol.

In particular, the polymer can have a polydispersity index M_(w)/M_(n)in the range of 1.0 to 10.0, more preferably in the range of 1.1 to 5.0and most preferably in the range of 1.2 to 3.

Preferably, the inert binder is a polymer having a glass transitiontemperature in the range of −70 to 160° C., preferably 0 to 150° C.,more preferably 50 to 140° C. and most preferably 70 to 130° C. Theglass transition temperature can be determined by measuring the DSC ofthe polymer (DIN EN ISO 11357, heating rate 10° C. per minute).

The weight ratio of the polymeric binder to the compound according tothe present invention is preferably in the range of 30:1 to 1:30,particularly in the range of 5:1 to 1:20 and more preferably in therange of 1:2 to 1:10.

According to a preferred embodiment the binder preferably comprisesrepeating units derived from styrene monomers and/or olefin monomers.Preferred polymeric binders can comprise at least 80%, preferably 90%and more preferably 99% by weight of repeating units derived fromstyrene monomers and/or olefins.

Styrene monomers are well known in the art. These monomers includestyrene, substituted styrenes with an alkyl substituent in the sidechain, such as α-methylstyrene and α-ethylstyrene, substituted styreneswith an alkyl substituent on the ring such as vinyltoluene andp-methylstyrene, halogenated styrenes such as monochlorostyrenes,dichlorostyrenes, tribromostyrenes and tetrabromostyrenes.

Olefin monomers consist of hydrogen and carbon atoms. These monomersinclude ethylene, propylene, butylenes, isoprene and 1,3-butadiene.

According to a preferred embodiment of the present invention, thepolymeric binder is polystyrene having a weight average molecular weightin the range of 50,000 to 2,000,000 g/mol, preferably 100,000 to 750,000g/mol, more preferably in the range of 150,000 to 600,000 g/mol and mostpreferably in the range of 200,000 to 500,000 g/mol.

Further examples of suitable binders are disclosed for example in US2007/0102696 A1. Especially suitable and preferred binders are describedin the following.

The binder should preferably be capable of forming a film, morepreferably a flexible film.

Suitable polymers as binders include poly(1,3-butadiene), polyphenylene,polystyrene, poly(α-methylstyrene), poly(α-vinylnaphtalene),poly(vinyltoluene), polyethylene, cis-polybutadiene, polypropylene,polyisoprene, poly(4-methyl-1-pentene), poly (4-methylstyrene),poly(chorotrifluoroethylene), poly(2-methyl-1,3-butadiene),poly(p-xylylene), poly(α-α-α′-α′ tetrafluoro-p-xylylene),poly[1,1-(2-methyl propane)bis(4-phenyl)carbonate], poly(cyclohexylmethacrylate), poly(chlorostyrene), poly(2,6-dimethyl-1,4-phenyleneether), polyisobutylene, poly(vinyl cyclohexane), poly(vinylcinnamate),poly(4-vinylbiphenyl), 1,4-polyisoprene, polynorbornene,poly(styrene-block-butadiene); 31% wt styrene,poly(styrene-block-butadiene-block-styrene); 30% wt styrene,poly(styrene-co-maleic anhydride) (and ethylene/butylene) 1-1.7% maleicanhydride, poly(styrene-block-ethylene/butylene-block-styrene) triblockpolymer 13% styrene,poly(styrene-block-ethylene-propylene-block-styrene) triblock polymer37% wt styrene, poly(styrene-block-ethylene/butylene-block-styrene)triblock polymer 29% wt styrene, poly(1-vinylnaphthalene),poly(1-vinylpyrrolidone-co-styrene) 64% styrene,poly(1-vinylpyrrolidone-co-vinyl acetate) 1.3:1, poly(2-chlorostyrene),poly(2-vinylnaphthalene), poly(2-vinylpyridine-co-styrene) 1:1,poly(4,5-Difluoro-2,2-bis(CF3)-1,3-dioxole-co-tetrafluoroethylene)Teflon, poly(4-chlorostyrene), poly(4-methyl-1-pentene),poly(4-methylstyrene), poly(4-vinylpyridine-co-styrene) 1:1,poly(alpha-methylstyrene), poly(butadiene-graft-poly(methylacrylate-co-acrylonitrile)) 1:1:1, poly(butyl methacrylate-co-isobutylmethacrylate) 1:1, poly(butyl methacrylate-co-methyl methacrylate) 1:1,poly(cyclohexylmethacrylate), poly(ethylene-co-1-butene-co-1-hexene)1:1:1, poly(ethylene-co-ethylacrylate-co-maleic anhydride); 2%anhydride, 32% ethyl acrylate, poly(ethylene-co-glycidyl methacrylate)8% glycidyl methacrylate, poly(ethylene-co-methyl acrylate-co-glycidylmeth-acrylate) 8% glycidyl metha-crylate 25% methyl acrylate,poly(ethylene-co-octene) 1:1,poly(ethylene-co-propylene-co-5-methylene-2-norbornene) 50% ethylene,poly(ethylene-co-tetrafluoroethylene) 1:1, poly(isobutyl methacrylate),poly(isobutylene), poly(methyl methacrylate)-co-(fluoresceinO-methacrylate) 80% methyl methacrylate, poly(methylmethacrylate-co-butyl methacrylate) 85% methyl methacrylate, poly(methylmethacrylate-co-ethyl acrylate) 5% ethyl acrylate,poly(propylene-co-butene) 12% 1-butene, poly(styrene-co-allyl alcohol)40% allyl alcohol, poly(styrene-co-maleic anhydride) 7% maleicanhydride, poly(styrene-co-maleic anhydride) cumene terminated (1.3:1),poly(styrene-co-methyl methacrylate) 40% styrene,poly(vinyltoluene-co-alpha-methylstyrene) 1:1, poly-2-vinylpyridine,poly-4-vinylpyridine, poly-alpha-pinene, polymethylmethacrylate,polybenzylmethacrylate, polyethylmethacrylate, polyethylene,polyethylene terephthalate, polyethylene-co-ethylacrylate 18% ethylacrylate, polyethylene-co-vinylacetate 12% vinyl acetate,polyethylene-graft-maleic anhydride 0.5% maleic anhydride,polypropylene, polypropylene-graft-maleic anhydride 8-10% maleicanhydride, polystyrenepoly(styrene-block-ethylene/butylene-block-styrene) graft maleicanhydride 2% maleic anhydride 1:1:1 others,poly(styrene-block-butadiene) branched 1:1,poly(styrene-block-butadiene-block-styrene), 30% styrene,poly(styrene-block-isoprene) 10% wt styrene,poly(styrene-block-isoprene-block-styrene) 17% wt styrene,poly(styrene-co-4-chloromethylstyrene-co-4-methoxymethylstyrene 2:1:1,polystyrene-co-acrylonitrile 25% acrylonitrile,polystyrene-co-alpha-methylstyrene 1:1, polystyrene-co-butadiene 4%butadiene, polystyrene-co-butadiene 45% styrene,polystyrene-co-chloromethylstyrene 1:1, polyvinylchloride,polyvinylcinnamate, polyvinylcyclohexane, polyvinylidenefluoride,polyvinylidenefluoride-co-hexafluoropropylene assume 1:1,poly(styrene-block-ethylene/propylene-block-styrene) 30% styrene,poly(styrene-block-ethylene/propylene-block-styrene) 18% styrene,poly(styrene-block-ethylene/propylene-block-styrene) 13% styrene,poly(styrene-block ethylene block-ethylene/propylene-block styrene) 32%styrene, poly(styrene-block ethylene block-ethylene/propylene-blockstyrene) 30% styrene,poly(styrene-block-ethylene/butylene-block-styrene) 31% styrene,poly(styrene-block-ethylene/butylene-block-styrene) 34% styrene,poly(styrene-block-ethylene/butylene-block-styrene) 30% styrene,poly(styrene-block-ethylene/butylene-block-styrene) 60%, styrene,branched or non-branched polystyrene-block-polybutadiene,polystyrene-block(polyethylene-ran-butylene)-block-polystyrene,polystyrene-block-polybutadiene-block-polystyrene,polystyrene-(ethylene-propylene)-diblock-copolymers (e.g.KRATON®-G1701E, Shell), poly(propylene-co-ethylene) andpoly(styrene-co-methylmethacrylate).

Preferred insulating binders to be used in the formulations as describedbefore are polystryrene, poly(α-methylstyrene), polyvinylcinnamate,poly(4-vinylbiphenyl), poly(4-methylstyrene), and polymethylmethacrylate.

Most preferred insulating binders are polystyrene and polymethylmethacrylate.

The binder can also be selected from crosslinkable binders, like e.g.acrylates, epoxies, vinylethers, thiolenes etc. The binder can also bemesogenic or liquid crystalline.

The organic binder may itself be a semiconductor, in which case it willbe referred to herein as a semiconducting binder. The semiconductingbinder is still preferably a binder of low permittivity as hereindefined. Semiconducting binders for use in the present inventionpreferably have a number average molecular weight (M_(n)) of at least1500-2000, more preferably at least 3000, even more preferably at least4000 and most preferably at least 5000. The semiconducting binderpreferably has a charge carrier mobility of at least 10⁻⁵ cm²V⁻¹s⁻¹,more preferably at least 10⁻⁴ cm²V⁻¹s⁻¹.

A preferred semiconducting binder comprises a homo-polymer or copolymer(including block-copolymer) containing arylamine (preferablytriarylamine).

To produce thin layers in BHJ OPV devices the compounds, compositionsand formulations of the present invention may be deposited by anysuitable method. Liquid coating of devices is more desirable than vacuumdeposition techniques. Solution deposition methods are especiallypreferred. The formulations of the present invention enable the use of anumber of liquid coating techniques. Preferred deposition techniquesinclude, without limitation, dip coating, spin coating, ink jetprinting, nozzle printing, letter-press printing, screen printing,gravure printing, doctor blade coating, roller printing, reverse-rollerprinting, offset lithography printing, dry offset lithography printing,flexographic printing, web printing, spray coating, curtain coating,brush coating, slot dye coating or pad printing. For the fabrication ofOPV devices and modules area printing method compatible with flexiblesubstrates are preferred, for example slot dye coating, spray coatingand the like.

Suitable solutions or formulations containing the mixture of a p-typeOSC compound and an n-type OSC compound must be prepared. In thepreparation of formulations, suitable solvent must be selected to ensurefull dissolution of both component, p-type and n-type and take intoaccount the boundary conditions (for example rheological properties)introduced by the chosen printing method.

Organic solvents are generally used for this purpose. Typical solventscan be aromatic solvents, halogenated solvents or chlorinated solvents,including chlorinated aromatic solvents. Examples include, but are notlimited to chlorobenzene, 1,2-dichlorobenzene, chloroform,1,2-dichloroethane, dichloromethane, carbon tetrachloride, toluene,cyclohexanone, ethylacetate, tetrahydrofuran, anisole,2,4-dimethylanisole, 1-methylnaphthalene, morpholine, toluene, o-xylene,m-xylene, p-xylene, 1,4-dioxane, acetone, methylethylketone,1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane,ethyl acetate, n-butyl acetate, N,N-dimethylformamide,dimethylacetamide, dimethylsulfoxide, 1,5-dimethyltetraline,propiophenone, acetophenone, tetraline, 2-methylthiophene,3-methylthiophene, decaline, indane, methyl benzoate, ethyl benzoate,mesitylene and combinations thereof.

The OPV device can for example be of any type known from the literature(see e.g. Waldauf et al., Appl. Phys. Lett., 2006, 89, 233517).

A first preferred OPV device according to the present inventioncomprises the following layers (in the sequence from bottom to top):

-   -   optionally a substrate,    -   a high work function electrode, preferably comprising a metal        oxide, like for example ITO, serving as anode,    -   an optional conducting polymer layer or hole transport layer,        preferably comprising an organic polymer or polymer blend, for        example of PEDOT:PSS (poly(3,4-ethylenedioxythiophene):        poly(styrene-sulfonate), or TBD        (N,N′-dyphenyl-N-N′-bis(3-methylphenyl)-1,1′biphenyl-4,4′-diamine)        or NBD        (N,N′-dyphenyl-N-N′-bis(1-napthylphenyl)-1,1′biphenyl-4,4′-diamine),    -   a layer, also referred to as “photoactive layer”, comprising a        p-type and an n-type organic semiconductor, which can exist for        example as a p-type/n-type bilayer or as distinct p-type and        n-type layers, or as blend or p-type and n-type semiconductor,        forming a BHJ,    -   optionally a layer having electron transport properties, for        example comprising LiF or PFN,    -   a low work function electrode, preferably comprising a metal        like for example aluminium, serving as cathode,    -   wherein at least one of the electrodes, preferably the anode, is        transparent to visible light, and    -   wherein the p-type semiconductor and/or the n-type semiconductor        is a compound according to the present invention.

A second preferred OPV device according to the present invention is aninverted OPV device and comprises the following layers (in the sequencefrom bottom to top):

-   -   optionally a substrate,    -   a high work function metal or metal oxide electrode, comprising        for example ITO, serving as cathode,    -   a layer having hole blocking properties, preferably comprising        an organic polymer, polymer blend, metal or metal oxide like        TiO_(x), ZnO_(x), Ca, Mg, poly(ethyleneimine),        poly(ethyleneimine) ethoxylated or poly        [(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)],    -   a photoactive layer comprising a p-type and an n-type organic        semiconductor, situated between the electrodes, which can exist        for example as a p-type/n-type bilayer or as distinct p-type and        n-type layers, or as blend or p-type and n-type semiconductor,        forming a BHJ,    -   an optional conducting polymer layer or hole transport layer,        preferably comprising an organic polymer or polymer blend, metal        or metal oxide, for example PEDOT:PSS, nafion, a substituted        triaryl amine derivative like for example TBD or NBD, or WO_(x),        MoO_(x), NiO_(x), Pd or Au,    -   an electrode comprising a high work function metal like for        example silver, serving as anode,    -   wherein at least one of the electrodes, preferably the cathode,        is transparent to visible light, and    -   wherein the p-type semiconductor and/or the n-type semiconductor        is a compound according to the present invention.

In the OPV devices of the present invention the p-type and n-typesemiconductor materials are preferably selected from the materials, likethe compound/polymer/fullerene systems, as described above When thephotoactive layer is deposited on the substrate, it forms a BHJ thatphase separates at nanoscale level. For discussion on nanoscale phaseseparation see Dennler et al, Proceedings of the IEEE, 2005, 93 (8),1429 or Hoppe et al, Adv. Func. Mater, 2004, 14(10), 1005. An optionalannealing step may be then necessary to optimize blend morpohology andconsequently OPV device performance.

Another method to optimize device performance is to prepare formulationsfor the fabrication of OPV(BHJ) devices that may include high boilingpoint additives to promote phase separation in the right way.1,8-octanedithiol, 1,8-diiodooctane, nitrobenzene, chloronaphthalene,and other additives have been used to obtain high-efficiency solarcells. Examples are disclosed in J. Peet, et al, Nat. Mater., 2007, 6,497 or Frechet et al. J. Am. Chem. Soc., 2010, 132, 7595-7597.

Another preferred embodiment of the present invention relates to the useof a compound or composition according to the present invention as dye,hole transport layer, hole blocking layer, electron transport layerand/or electron blocking layer in a DSSC or a perovskite-based solarcell (PSC), and to a DSSC or PSC comprising a compound or compositionaccording to the present invention.

DSSCs and PSCs can be manufactured as described in the literature, forexample in Chem. Rev. 2010, 110, 6595-6663, Angew. Chem. Int. Ed. 2014,53, 2-15 or in WO2013171520A1

A preferred OE device according to the present invention is a solarcell, preferably a PSC, comprising a light absorber which is at least inpart inorganic as described below.

In a solar cell comprising the light absorber according to the presentinvention there are no restrictions per se with respect to the choice ofthe light absorber material which is at least in part inorganic.

The term “at least in part inorganic” means that the light absorbermaterial may be selected from metalorganic complexes or materials whichare substantially inorganic and possess preferably a crystallinestructure where single positions in the crystalline structure may beallocated by organic ions.

Preferably, the light absorber comprised in the solar cell according tothe present invention has an optical band-gap≤2.8 eV and ≥0.8 eV.

Very preferably, the light absorber in the solar cell according to thepresent invention has an optical band-gap≤2.2 eV and ≥1.0 eV.

The light absorber used in the solar cell according to the presentinvention does preferably not contain a fullerene. The chemistry offullerenes belongs to the field of organic chemistry. Thereforefullerenes do not fulfil the definition of being “at least in partinorganic” according to the present invention.

Preferably, the light absorber which is at least in part inorganic is amaterial having perovskite structure or a material having 2D crystallineperovskite structure.

The term “perovskite” as used above and below denotes generally amaterial having a perovskite crystalline structure or a 2D crystallineperovskite structure.

The term perovskite solar cell (PSC) means a solar cell comprising alight absorber which is a material having perovskite structure or amaterial having 2D crystalline perovskite structure.

The light absorber which is at least in part inorganic is withoutlimitation composed of a material having perovskite crystallinestructure, a material having 2D crystalline perovskite structure (e.g.CrystEngComm, 2010, 12, 2646-2662), Sb₂S₃ (stibnite),Sb₂(S_(x)Se_((x-1)))₃, PbS_(x)Se_((x-1)), CdS_(x)Se_((x-1)), ZnTe, CdTe,ZnSxSe_((x-1)), InP, FeS, FeS₂, Fe₂S₃, Fe₂SiS₄, Fe₂GeS₄, Cu₂S, CuInGa,CuIn(Se_(x)S_((1-x)))₂, Cu₃Sb_(x)Bi_((x-1)), (S_(y)Se_((y-1)))₃,Cu₂SnS₃, SnS_(x)Se_((x-1)), Ag₂S, AgBiS₂, BiSI, BiSeI,Bi₂(S_(x)Se_((x-1)))₃, BiS_((1-x))Se_(x)I, WSe₂, AlSb, metal halides(e.g. BiI₃, Cs₂SnI₆), chalcopyrite (e.g.CuIn_(x)Ga_((1-x))(S_(y)Se_((1-y)))₂), kesterite (e.g. Cu₂ZnSnS₄,Cu₂ZnSn(Se_(x)S_((1-x)))₄, Cu₂Zn(Sn_(1-x)Ge_(x))S₄) and metal oxide(e.g. CuO, Cu₂O) or a mixture thereof.

Preferably, the light absorber which is at least in part inorganic is aperovskite.

In the above definition for light absorber, x and y are eachindependently defined as follows: (0≤x≤1) and (0≤y≤1).

Very preferably, the light absorber is a special perovskite namely ametal halide perovskite as described in detail above and below. Mostpreferably, the light absorber is an organic-inorganic hybrid metalhalide perovskite contained in the perovskite solar cell (PSC).

In one particularly preferred embodiment of the invention, theperovskite denotes a metal halide perovskite with the formula ABX₃,

where

-   A is a monovalent organic cation, a metal cation or a mixture of two    or more of these cations-   B is a divalent cation and-   X is F, Cl, Br, I, BF₄ or a combination thereof.

Preferably, the monovalent organic cation of the perovskite is selectedfrom alkylammonium, wherein the alkyl group is straight chain orbranched having 1 to 6 C atoms, formamidinium or guanidinium or whereinthe metal cation is selected from K⁺, Cs⁺ or Rb⁺.

Suitable and preferred divalent cations B are Ge²⁺, Sn²⁺ or Pb²⁺.

Suitable and preferred perovskite materials are CsSnI₃,CH₃NH₃Pb(I_(1-x)Cl_(x))₃, CH₃NH₃PbI₃, CH₃NH₃Pb(I_(1-x)Br_(x))₃,CH₃NH₃Pb(I_(1-x)(BF₄)_(x))₃, CH₃NH₃Sn(I_(1-x)Cl_(x))₃, CH₃NH₃SnI₃ orCH₃NH₃Sn(I_(1-x)Br_(x))₃ wherein x is each independently defined asfollows: (0<x≤1).

Further suitable and preferred perovskites may comprise two halidescorresponding to formula Xa_((3-x))Xb_((x)), wherein Xa and Xb are eachindependently selected from Cl, Br, or I, and x is greater than 0 andless than 3.

Suitable and preferred perovskites are also disclosed in WO 2013/171517,claims 52 to 71 and claims 72 to 79, which is entirely incorporatedherein by reference. The materials are defined as mixed-anionperovskites comprising two or more different anions selected from halideanions and chalcogenide anions. Preferred perovskites are disclosed onpage 18, lines 5 to 17. As described, the perovskite is usually selectedfrom CH₃NH₃PbBrI₂, CH₃NH₃PbBrCl₂, CH₃NH₃PbIBr₂, CH₃NH₃PbICl₂,CH₃NH₃SnF₂Br, CH₃NH₃SnF₂I and (H₂N═CH—NH₂)PbI_(3z)Br_(3(1-z)), wherein zis greater than 0 and less than 1.

The invention further relates to a solar cell comprising the lightabsorber, preferably a PSC, as described above and below, wherein thecompound according to the present invention is employed as a layerbetween one electrode and the light absorber layer.

The invention further relates to a solar cell comprising the lightabsorber, preferably a PSC, as described above and below, wherein thecompound according to the present invention is an n-type semiconductorand is comprised in an electron-selective layer.

The electron-selective layer is defined as a layer providing a highelectron conductivity and a low hole conductivity favoringelectron-charge transport.

The invention further relates to a solar cell comprising the lightabsorber, preferably a PSC, as described above and below, wherein thecompound according to the present invention is a p-type semiconductorand is comprised in a hole-selective layer.

The hole-selective layer is defined as a layer providing a high holeconductivity and a low electron conductivity favoring hole-chargetransport.

The invention further relates to a solar cell comprising the lightabsorber, preferably a PSC, as described above and below, wherein thecompound according to the present invention is an n-type semiconductorand is employed as electron transport material (ETM) or as hole blockingmaterial as part of the electron selective layer.

The invention further relates to a solar cell comprising the lightabsorber, preferably a PSC, as described above and below, wherein thecompound according to the present invention is a p-type semiconductorand is employed as hole transport material (HTM) or as electron blockingmaterial as part of the hole selective layer. The device architecture ofa PSC device according to the present invention can be of any type knownfrom the literature.

A first preferred device architecture of a PSC device according to thepresent invention comprises the following layers (in the sequence frombottom to top):

-   -   optionally a substrate which, in any combination, can be        flexible or rigid and transparent, semi-transparent or        non-transparent and electrically conductive or non-conductive;    -   a high work function electrode, preferably comprising a doped        metal oxide, for example fluorine-doped tin oxide (FTO),        tin-doped indium oxide (ITO), or aluminium-doped zinc oxide;    -   optionally an electron-selective layer which comprises one or        more electron-transporting materials which, in some cases, can        also be a dense layer and/or be composed of nanoparticles, and        which preferably comprises a metal oxide such as TiO₂, ZnO₂,        SnO₂, Y₂O₅, Ga₂O₃, SrTiO₃, BaTiO₃ or combinations thereof;    -   optionally a porous scaffold which can be conducting,        semi-conducting or insulating, and which preferably comprises a        metal oxide such as TiO₂, ZnO₂, SnO₂, Y₂O₅, Ga₂O₃, SrTiO₃,        BaTiO₃, Al₂O₃, ZrO₂, SiO₂ or combinations thereof, and which is        preferably composed of nanoparticles, nanorods, nanoflakes,        nanotubes or nanocolumns;    -   a layer comprising a light absorber which is at least in part        inorganic, particularly preferably a metal halide perovskite as        described above which, in some cases, can also be a dense or        porous layer and which optionally partly or fully infiltrates        into the underlying layer;    -   optionally a hole selective layer which comprises one or more        hole-transporting materials which, in some cases, can also        comprise additives such as lithium salts, for example LiY, where        Y is a monovalent organic anion, preferably        bis(trifluoromethylsulfonyl)imide, tertiary amines such as        4-tert-butylpyridine, or any other covalent or ionic compounds,        for example        tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)-cobalt(III)        tris(bis(trifluoromethylsulfonyl)imide)), which can enhance the        properties of the hole selective layer, for example the        electrical conductivity, and/or facilitate its processing; and a        back electrode which can be metallic, for example made of Au,        Ag, Al, Cu, Ca, Ni or combinations thereof, or non-metallic and        transparent, semi-transparent or non-transparent.        wherein the PSC device comprises at least one of        the electron-selective layer as described above which comprises        a compound according to the present invention which is an n-type        semiconductor,        the hole-selective layer as described above which comprises a        compound according to the present invention which is a p-type        semiconductor.

A second preferred device architecture of a PSC device according to thepresent invention comprises the following layers (in the sequence frombottom to top):

-   -   optionally a substrate which, in any combination, can be        flexible or rigid and transparent, semi-transparent or        non-transparent and electrically conductive or non-conductive;    -   a high work function electrode, preferably comprising a doped        metal oxide, for example fluorine-doped tin oxide (FTO),        tin-doped indium oxide (ITO), or aluminium-doped zinc oxide;    -   optionally a hole injection layer which, for example, changes        the work function of the underlying electrode, and/or modifies        the surface of the underlying layer and/or helps to planarize        the rough surface of the underlying layer and which, in some        cases, can also be a monolayer;    -   a hole selective layer, which comprises one or more        hole-transporting materials, and which, in some cases, can also        comprise additives such as lithium salts, for example LiY, where        Y is a monovalent organic anion, preferably        bis(trifluoromethylsulfonyl)imide, tertiary amines such as        4-tert-butylpyridine, or any other covalent or ionic compounds,        for example        tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)-cobalt(III)        tris(bis(trifluoromethylsulfonyl)imide)), which can enhance the        properties of the hole selective layer, for example the        electrical conductivity, and/or facilitate its processing;    -   a layer comprising a light absorber which is at least in part        inorganic, particularly preferably a metal halide perovskite as        described or preferably described above;    -   optionally an electron-selective layer, which comprises one or        more electron-transporting materials, which, in some cases, can        also be a dense layer and/or be composed of nanoparticles, and        which, for example, can comprise a metal oxide such as TiO₂,        ZnO₂, SnO₂, Y₂O₅, Ga₂O₃, SrTiO₃, BaTiO₃ or combinations thereof,        and/or which can comprise a substituted fullerene, for example        [6,6]-phenyl C61-butyric acid methyl ester, and/or which can        comprise a molecular, oligomeric or polymeric electron-transport        material, for example        2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline, or a mixture        thereof;        and a back electrode which can be metallic, for example made of        Au, Ag, Al, Cu, Ca, Ni or combinations thereof, or non-metallic        and transparent, semi-transparent or non-transparent,        wherein the PSC device comprises at least one of        the electron-selective layer as described above which comprises        a compound according to the present invention which is an n-type        semiconductor,        the hole-selective layer as described above which comprises a        compound according to the present invention which is a p-type        semiconductor.

To produce electron- or hole-selective layers in PSC devices accordingto the present invention, the compounds according to the presentinvention, optionally together with other compounds or additives in theform of blends or mixtures, may be deposited by any suitable method.Liquid coating of devices is more desirable than vacuum depositiontechniques. Solution deposition methods are especially preferred.Formulations comprising the compounds according to the present inventionenable the use of a number of liquid coating techniques. Preferreddeposition techniques include, without limitation, dip coating, spincoating, ink jet printing, nozzle printing, letter-press printing,screen printing, gravure printing, doctor blade coating, rollerprinting, reverse-roller printing, offset lithography printing, dryoffset lithography printing, flexographic printing, web printing, spraycoating, curtain coating, brush coating, slot die coating or padprinting. For the fabrication of PSC devices and modules, depositiontechniques for large area coating are preferred, for example slot diecoating or spray coating.

Formulations that can be used to produce electron- or hole-selectivelayers in optoelectronic devices according to the present invention,preferably in PSC devices comprise one or more compounds according tothe present invention or preferred embodiments as described above in theform of blends or mixtures optionally together with one or more furtherelectron transport materials and/or hole blocking materials and/orbinders and/or other additives as described above and below, and one ormore solvents.

The formulation may include or comprise, essentially consist of orconsist of the said necessary or optional constituents as describedabove or below. All compounds or components which can be used in theformulations are either known or commercially available, or can besynthesised by known processes.

The formulation as described before may be prepared by a process whichcomprises:

-   (i) first mixing a compound according to the present invention,    optionally a binder or a precursor of a binder as described before,    optionally a further electron transport material, optionally one or    more further additives as described above and below and a solvent or    solvent mixture as described above and below and-   (ii) applying such mixture to a substrate; and optionally    evaporating the solvent(s) to form an electron selective layer    according to the present invention.

In step (i) the solvent may be a single solvent for the compoundaccording to the present invention and the organic binder and/or furtherelectron transport material may each be dissolved in a separate solventfollowed by mixing the resultant solutions to mix the compounds.

Alternatively, the binder may be formed in situ by mixing or dissolvinga compound according to the present invention in a precursor of abinder, for example a liquid monomer, oligomer or crosslinkable polymer,optionally in the presence of a solvent, and depositing the mixture orsolution, for example by dipping, spraying, painting or printing it, ona substrate to form a liquid layer and then curing the liquid monomer,oligomer or crosslinkable polymer, for example by exposure to radiation,heat or electron beams, to produce a solid layer. If a preformed binderis used it may be dissolved together with the compound according to thepresent invention in a suitable solvent as described before, and thesolution deposited for example by dipping, spraying, painting orprinting it on a substrate to form a liquid layer and then removing thesolvent to leave a solid layer. It will be appreciated that solvents arechosen which are able to dissolve all ingredients of the formulation,and which upon evaporation from the solution blend give a coherentdefect free layer.

Besides the said components, the formulation as described before maycomprise further additives and processing assistants. These include,inter alia, surface-active substances (surfactants), lubricants andgreases, additives which modify the viscosity, additives which increasethe conductivity, dispersants, hydrophobicising agents, adhesionpromoters, flow improvers, antifoams, deaerating agents, diluents, whichmay be reactive or unreactive, fillers, assistants, processingassistants, dyes, pigments, stabilisers, sensitisers, nanoparticles andinhibitors.

Additives can be used to enhance the properties of the electronselective layer and/or the properties of any of the neighbouring layersand/or the performance of the optoelectronic device according to thepresent invention. Additives can also be used to facilitate thedeposition, the processing or the formation of the electron selectivelayer and/or the deposition, the processing or the formation of any ofthe neighbouring layers. Preferably, one or more additives are usedwhich enhance the electrical conductivity of the electron selectivelayer and/or passivate the surface of any of the neighbouring layers.

Suitable methods to incorporate one or more additives include, forexample exposure to a vapor of the additive at atmospheric pressure orat reduced pressure, mixing a solution or solid containing one or moreadditives and a material or a formulation as described or preferablydescribed before, bringing one or more additives into contact with amaterial or a formulation as described before, by thermal diffusion ofone or more additives into a material or a formulation as describedbefore, or by ion-implantation of one or more additives into a materialor a formulation as described before.

Additives used for this purpose can be organic, inorganic, metallic orhybrid materials. Additives can be molecular compounds, for exampleorganic molecules, salts, ionic liquids, coordination complexes ororganometallic compounds, polymers or mixtures thereof. Additives canalso be particles, for example hybrid or inorganic particles, preferablynanoparticles, or carbon based materials such as fullerenes, carbonnanotubes or graphene flakes.

Examples for additives that can enhance the electrical conductivity arefor example halogens (e.g. I₂, Cl₂, Br₂, ICl, ICl₃, IBr and IF), Lewisacids (e.g. PF₅, AsF₅, SbF₅, BF₃, BCl₃, SbCl₅, BBr₃ and SO₃), protonicacids, organic acids, or amino acids (e.g. HF, HCl, HNO₃, H₂SO₄, HClO₄,FSO₃H and ClSO₃H), transition metal compounds (e.g. FeCl₃, FeOCl,Fe(ClO₄)₃, Fe(4-CH₃C₆H₄SO₃)₃, TiCl₄, ZrCl₄, HfCl₄, NbF₅, NbCl₅, TaCl₅,MoF₅, MoCl₅, WF₅, WCl₆, UF₆ and LnCl₃ (wherein Ln is a lanthanoid)),anions (e.g. Cl⁻, Br⁻, I⁻, I₃ ⁻, HSO₄ ⁻, SO₄ ²⁻, NO₃ ⁻, ClO₄ ⁻, BF₄ ⁻,PF₆ ⁻, AsF₆ ⁻, SbF₆ ⁻, FeCl₄ ⁻, Fe(CN)₆ ³⁻ and anions of varioussulfonic acids, such as aryl-SO₃ ⁻), cations (e.g. H⁺, Li⁺, Na⁺, K⁺,Rb⁺, Cs⁺, Co³⁻ and Fe³⁺), O₂, redox active salts (e.g. XeOF₄, (NO₂ ⁺)(SbF₆ ⁻), (NO₂ ⁺) (SbCl₆ ⁻), (NO₂ ⁺) (BF₄ ⁻), NOBF₄, NOPF₆, AgClO₄,H₂IrCl₆ and La(NO₃)₃·6H₂O), strongly electron-accepting organicmolecules (e.g. 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane(F4-TCNQ)), transition metal oxides (e.g. WO₃, Re₂O₇ and MoO₃),metal-organic complexes of cobalt, iron, bismuth and molybdenum,(p-BrC₆H₄)₃NSbCl₆, bismuth(III) tris(trifluoroacetate), FSO₂OOSO₂F,acetylcholine, R₄N⁺, (R is an alkyl group), R₄P⁺ (R is a linear orbranched alkyl group 1 to 20), R₆As⁺ (R is an alkyl group), R₃S⁺ (R isan alkyl group) and ionic liquids (e.g. 1-Ethyl-3-methylimidazoliumbis(trifluoromethylsulfonyl)imide). Suitable cobalt complexes beside oftris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine)-cobalt(III)tris(bis(trifluoromethylsulfonyl)imide)) are cobalt complex salts asdescribed in WO 2012/114315, WO 2012/114316, WO 2014/082706, WO2014/082704, EP 2883881 or JP 2013-131477.

Suitable lithium salts are beside of lithiumbis(trifluoromethylsulfonyl)imide, lithiumtris(pentafluoroethyl)trifluorophosphate, lithium dicyanamide, lithiummethylsulfate, lithium trifluormethanesulfonate, lithiumtetracyanoborate, lithium dicyanamide, lithium tricyanomethide, lithiumthiocyanate, lithium chloride, lithium bromide, lithium iodide, lithiumhexafluoroposphate, lithium tetrafluoroborate, lithium perchlorate,lithium hexafluoroantimonate, lithium hexafluoroarsenate or acombination of two or more. A preferred lithium salt is lithiumbis(trifluoromethylsulfonyl)imide.

Preferably, the formulation comprises from 0.1 mM to 50 mM, preferablyfrom 5 to 20 mM of the lithium salt.

Suitable device structures for PSCs comprising a compound according tothe present invention and a mixed halide perovskite are described in WO2013/171517, claims 52 to 71 and claims 72 to 79, which is entirelyincorporated herein by reference.

Suitable device structures for PSCs comprising a compound formula and adielectric scaffold together with a perovskite are described in WO2013/171518, claims 1 to 90 or WO 2013/171520, claims 1 to 94 which areentirely incorporated herein by reference.

Suitable device structures for PSCs comprising a compound according tothe present invention, a semiconductor and a perovskite are described inWO 2014/020499, claims 1 and 3 to 14, which is entirely incorporatedherein by reference The surface-increasing scaffold structure describedtherein comprises nanoparticles which are applied and/or fixed on asupport layer, e.g. porous TiO₂.

Suitable device structures for PSCs comprising a compounds of formulaand comprising a planar heterojunction are described in WO 2014/045021,claims 1 to 39, which is entirely incorporated herein by reference. Sucha device is characterized in having a thin film of a light-absorbing orlight-emitting perovskite disposed between n-type (electron conducting)and p-type (hole-conducting) layers. Preferably, the thin film is acompact thin film.

The invention further relates to a method of preparing a PSC asdescribed above or below, the method comprising the steps of:

-   -   providing a first and a second electrode;    -   providing an electron-selective layer and/or hole-selective        layer at least one of which comprises a compound according to        the present invention.

The invention relates furthermore to a tandem device comprising at leastone device according to the present invention as described above andbelow. Preferably, the tandem device is a tandem solar cell.

The tandem device or tandem solar cell according to the presentinvention may have two semi-cells wherein one of the semi cellscomprises the compounds, oligomers or polymers in the active layer asdescribed or preferably described above. There exists no restriction forthe choice of the other type of semi cell which may be any other type ofdevice or solar cell known in the art.

There are two different types of tandem solar cells known in the art.The so called 2-terminal or monolithic tandem solar cells have only twoconnections. The two subcells (or synonymously semi cells) are connectedin series. Therefore, the current generated in both subcells isidentical (current matching). The gain in power conversion efficiency isdue to an increase in voltage as the voltages of the two subcells addup. The other type of tandem solar cells is the so called 4-terminal orstacked tandem solar cell. In this case, both subcells are operatedindependently. Therefore, both subcells can be operated at differentvoltages and can also generate different currents. The power conversionefficiency of the tandem solar cell is the sum of the power conversionefficiencies of the two subcells.

The invention furthermore relates to a module comprising a deviceaccording to the present invention as described before or preferablydescribed before.

The compounds and compositions of the present invention can also be usedas dye or pigment in other applications, for example as an ink dye,laser dye, fluorescent marker, solvent dye, food dye, contrast dye orpigment in coloring paints, inks, plastics, fabrics, cosmetics, food andother materials.

The compounds and compositions of the present invention are alsosuitable for use in the semiconducting channel of an OFET. Accordingly,the invention also provides an OFET comprising a gate electrode, aninsulating (or gate insulator) layer, a source electrode, a drainelectrode and an organic semiconducting channel connecting the sourceand drain electrodes, wherein the organic semiconducting channelcomprises a compound and compositions according to the presentinvention. Other features of the OFET are well known to those skilled inthe art.

OFETs where an OSC material is arranged as a thin film between a gatedielectric and a drain and a source electrode, are generally known, andare described for example in U.S. Pat. Nos. 5,892,244, 5,998,804,6,723,394 and in the references cited in the background section. Due tothe advantages, like low cost production using the solubility propertiesof the compounds according to the present invention and thus theprocessibility of large surfaces, preferred applications of these OFETsare such as integrated circuitry, TFT displays and securityapplications.

The gate, source and drain electrodes and the insulating andsemiconducting layer in the OFET device may be arranged in any sequence,provided that the source and drain electrode are separated from the gateelectrode by the insulating layer, the gate electrode and thesemiconductor layer both contact the insulating layer, and the sourceelectrode and the drain electrode both contact the semiconducting layer.

An OFET device according to the present invention preferably comprises:

-   -   a source electrode,    -   a drain electrode,    -   a gate electrode,    -   a semiconducting layer,    -   one or more gate insulator layers,    -   optionally a substrate.        wherein the semiconducting layer comprises a compound according        to the present invention.

The OFET device can be a top gate device or a bottom gate device.Suitable structures and manufacturing methods of an OFET device areknown to the skilled in the art and are described in the literature, forexample in US 2007/0102696 A1.

The gate insulator layer preferably comprises a fluoropolymer, like e.g.the commercially available Cytop 809M® or Cytop 107M® (from AsahiGlass). Preferably the gate insulator layer is deposited, e.g. byspin-coating, doctor blading, wire bar coating, spray or dip coating orother known methods, from a formulation comprising an insulator materialand one or more solvents with one or more fluoro atoms (fluorosolvents),preferably a perfluorosolvent. A suitable perfluorosolvent is e.g. FC75®(available from Acros, catalogue number 12380). Other suitablefluoropolymers and fluorosolvents are known in prior art, like forexample the perfluoropolymers Teflon AF® 1600 or 2400 (from DuPont) orFluoropel® (from Cytonix) or the perfluorosolvent FC 43® (Acros, No.12377). Especially preferred are organic dielectric materials having alow permittivity (or dielectric constant) from 1.0 to 5.0, verypreferably from 1.8 to 4.0 (“low k materials”), as disclosed for examplein US 2007/0102696 A1 or U.S. Pat. No. 7,095,044.

In security applications, OFETs and other devices with semiconductingmaterials according to the present invention, like transistors ordiodes, can be used for RFID tags or security markings to authenticateand prevent counterfeiting of documents of value like banknotes, creditcards or ID cards, national ID documents, licenses or any product withmonetary value, like stamps, tickets, shares, cheques etc.

Alternatively, the compounds and compositions (hereinafter referred toas “materials”) according to the present invention can be used in OLEDs,e.g. as the active display material in a flat panel displayapplications, or as backlight of a flat panel display like e.g. a liquidcrystal display. Common OLEDs are realized using multilayer structures.An emission layer is generally sandwiched between one or moreelectron-transport and/or hole-transport layers. By applying an electricvoltage electrons and holes as charge carriers move towards the emissionlayer where their recombination leads to the excitation and henceluminescence of the lumophor units contained in the emission layer. Thematerials according to the present invention may be employed in one ormore of the charge transport layers and/or in the emission layer,corresponding to their electrical and/or optical properties. Furthermoretheir use within the emission layer is especially advantageous, if thematerials according to the present invention show electroluminescentproperties themselves or comprise electroluminescent groups orcompounds. The selection, characterization as well as the processing ofsuitable monomeric, oligomeric and polymeric compounds or materials forthe use in OLEDs is generally known by a person skilled in the art, see,e.g., Müller et al, Synth. Metals, 2000, 111-112, 31-34, Alcala et al.,J. Appl. Phys., 2000, 88, 7124-7128 and the literature cited therein.

According to another use, the materials according to the presentinvention, especially those showing photoluminescent properties, may beemployed as materials of light sources, e.g. in display devices, asdescribed in EP 0 889 350 A1 or by C. Weder et al., Science, 1998, 279,835-837.

A further aspect of the invention relates to both the oxidised andreduced form of the materials according to the present invention. Eitherloss or gain of electrons results in formation of a highly delocalisedionic form, which is of high conductivity. This can occur on exposure tocommon dopants. Suitable dopants and methods of doping are known tothose skilled in the art, e.g. from EP 0 528 662, U.S. Pat. No.5,198,153 or WO 96/21659.

The doping process typically implies treatment of the semiconductormaterial with an oxidating or reducing agent in a redox reaction to formdelocalised ionic centres in the material, with the correspondingcounterions derived from the applied dopants. Suitable doping methodscomprise for example exposure to a doping vapor in the atmosphericpressure or at a reduced pressure, electrochemical doping in a solutioncontaining a dopant, bringing a dopant into contact with thesemiconductor material to be thermally diffused, and ion-implantantionof the dopant into the semiconductor material.

When electrons are used as carriers, suitable dopants are for examplehalogens (e.g., I₂, Cl₂, Br₂, ICI, ICl₃, IBr and IF), Lewis acids (e.g.,PF₅, AsF₅, SbF₅, BF₃, BCl₃, SbCl₅, BBr₃ and SO₃), protonic acids,organic acids, or amino acids (e.g., HF, HCl, HNO₃, H₂SO₄, HClO₄, FSO₃Hand CISO₃H), transition metal compounds (e.g., FeCl₃, FeOCl, Fe(ClO₄)₃,Fe(4-CH₃C₆H₄SO₃)₃, TiCl₄, ZrCl₄, HfCl₄, NbF₅, NbCl₅, TaCl₅, MoF₅, MoCl₅,WF₅, WCl₆, UF₆ and LnCl₃ (wherein Ln is a lanthanoid), anions (e.g.,Cl⁻, Br⁻, I⁻, I₃ ⁻, HSO₄ ⁻, SO₄ ²⁻, NO₃ ⁻, ClO₄ ⁻, BF₄ ⁻, PF₆ ⁻, ASF₆ ⁻,SbF₆ ⁻, FeCl₄ ⁻, Fe(CN)₆ ³⁻, and anions of various sulfonic acids, suchas aryl —SO₃ ⁻). When holes are used as carriers, examples of dopantsare cations (e.g., H⁺, Li⁺, Na⁺, K⁺, Rb⁺ and Cs⁺), alkali metals (e.g.,Li, Na, K, Rb, and Cs), alkaline-earth metals (e.g., Ca, Sr, and Ba),O₂, XeOF₄, (NO₂ ⁺) (SbF₆ ⁻), (NO₂ ⁺) (SbCl₆ ⁻), (NO₂ ⁺) (BF₄ ⁻), AgClO₄,H₂IrCl₆, La(NO₃)₃·6H₂O, FSO₂OOSO₂F, Eu, acetylcholine, R₄N⁺, (R is analkyl group), R₄P⁺ (R is an alkyl group), R₆As⁺ (R is an alkyl group),and R₃S⁺ (R is an alkyl group).

The conducting form of the materials according to the present inventioncan be used as an organic “metal” in applications including, but notlimited to, charge injection layers and ITO planarising layers in OLEDapplications, films for flat panel displays and touch screens,antistatic films, printed conductive substrates, patterns or tracts inelectronic applications such as printed circuit boards and condensers.

The materials according to the present invention may also be suitablefor use in organic plasmon-emitting diodes (OPEDs), as described forexample in Koller et al., Nat. Photonics, 2008, 2, 684.

According to another use, the materials according to the presentinvention can be used alone or together with other materials in or asalignment layers in LCD or OLED devices, as described for example in US2003/0021913. The use of charge transport compounds according to thepresent invention can increase the electrical conductivity of thealignment layer. When used in an LCD, this increased electricalconductivity can reduce adverse residual dc effects in the switchableLCD cell and suppress image sticking or, for example in ferroelectricLCDs, reduce the residual charge produced by the switching of thespontaneous polarisation charge of the ferroelectric LCs. When used inan OLED device comprising a light emitting material provided onto thealignment layer, this increased electrical conductivity can enhance theelectroluminescence of the light emitting material.

The materials according to the present invention having mesogenic orliquid crystalline properties can form oriented anisotropic films asdescribed above, which are especially useful as alignment layers toinduce or enhance alignment in a liquid crystal medium provided ontosaid anisotropic film.

According to another use, the materials according to the presentinvention are suitable for use in liquid crystal (LC) windows, alsoknown as smart windows.

The materials according to the present invention may also be combinedwith photoisomerisable compounds and/or chromophores for use in or asphotoalignment layers, as described in US 2003/0021913 A1.

According to another use, the materials according to the presentinvention, especially their water-soluble derivatives (for example withpolar or ionic side groups) or ionically doped forms, can be employed aschemical sensors or materials for detecting and discriminating DNAsequences. Such uses are described for example in L. Chen, D. W.McBranch, H. Wang, R. Helgeson, F. Wudl and D. G. Whitten, Proc. Natl.Acad. Sci. U.S.A., 1999, 96, 12287; D. Wang, X. Gong, P. S. Heeger, F.Rininsland, G. C. Bazan and A. J. Heeger, Proc. Natl. Acad. Sci. U.S.A.,2002, 99, 49; N. DiCesare, M. R. Pinot, K. S. Schanze and J. R.Lakowicz, Langmuir, 2002, 18, 7785; D. T. McQuade, A. E. Pullen, T. M.Swager, Chem. Rev., 2000, 100, 2537.

Unless the context clearly indicates otherwise, as used herein pluralforms of the terms herein are to be construed as including the singularform and vice versa.

Throughout the description and claims of this specification, the words“comprise” and “contain” and variations of the words, for example“comprising” and “comprises”, mean “including but not limited to”, andare not intended to (and do not) exclude other components.

It will be appreciated that variations to the foregoing embodiments ofthe invention can be made while still falling within the scope of theinvention. Each feature disclosed in this specification, unless statedotherwise, may be replaced by alternative features serving the same,equivalent or similar purpose. Thus, unless stated otherwise, eachfeature disclosed is one example only of a generic series of equivalentor similar features.

All of the features disclosed in this specification may be combined inany combination, except combinations where at least some of suchfeatures and/or steps are mutually exclusive. In particular, thepreferred features of the invention are applicable to all aspects of theinvention and may be used in any combination. Likewise, featuresdescribed in non-essential combinations may be used separately (not incombination).

Above and below, unless stated otherwise percentages are percent byweight and temperatures are given in degrees Celsius.

The invention will now be described in more detail by reference to thefollowing examples, which are illustrative only and do not limit thescope of the invention.

Example 1

Monomer M1 is prepared as follows.

1.1 Chloro-6-fluoro-benzo[1,2,5]thiadiazole

4-Chloro-5-fluoro-benzene-1,2-diamine (5.00 g; 31.1 mmol; 1.00 eq.) isdissolved in dry dichloromethane (70 cm³). Pyridine (15.1 cm³; 186 mmol;6.00 eq.) is added and the solution is cooled at 0° C. Thionyl chloride(18.1 cm³; 249 mmol; 8.00 eq.) is added dropwise under vigorousstirring. After completed addition, the reaction mixture is warmed to23° C. and stirred for 20 hours. The reaction mixture is carefullypoured on water (200 cm³). After 30 minutes stirring at 23° C., themixture is filtered through a pad of celite. The aqueous layer isextracted with dichloromethane (3×70 cm³). The combined organic layer isdried over magnesium sulphate, filtered off and concentrated to dryness.The residue is filtered through a pad of silica gel using petroleumether (40-60° C.):dichloromethane mixture 8:2 as an eluent to afford thetitle compound as a shiny off-white solid (2.50 g, 42%).

¹H NMR (400 MHz, CDCl₃): δ 8.15 (d, J=7.2 Hz, 1H), 7.76 (d, J=8.7 Hz,1H).

1.2: 5-Chloro-6-fluoro-4,7-bis-trimethylsilanyl-benzo[1,2,5]thiadiazole

To a solution of 5-chloro-6-fluoro-benzo[1,2,5]thiadiazole (3.00 g; 15.9mmol; 1.00 eq.) in anhydrous tetrahydrofuran (100 cm³) is added at −78°C. (diisopropylamino)lithium (23.9 cm³; 47.7 mmol; 3.00 eq.). Themixture is stirred at this temperature for 1 hour beforechlorotrimethylsilane (7.07 cm³; 55.7 mmol; 3.50 eq.) is added in oneportion. The reaction mixture is allowed to warm up at 23° C. and isstirred at this temperature for 15 hours. The mixture is poured on water(100 cm³). The aqueous layer is extracted with dichloromethane (2×50cm³). The combined organic layer is washed with brine, dried overmagnesium sulphate, filtered off and concentrated to dryness. Theresidue is purified by column chromatography using petroleum ether(40-60° C.):dichloromethane 95:5 to 7:3 gradient as an eluent to affordthe title compound as a yellow oil (2.74 g, 51%).

¹H NMR (400 MHz, CDCl₃): δ 0.60 (s, 9H), 0.52 (d, J=1.6 Hz, 9H).

4,7-Dibromo-5-chloro-6-fluoro-benzo[1,2,5]thiadiazole (M1)

To a solution of5-chloro-6-fluoro-4,7-bis-trimethylsilanyl-benzo[1,2,5]thiadiazole (2.74g; 8.23 mmol; 1.00 eq.) in chloroform (15 cm³) is added bromine (12.7cm³; 246 mmol; 30.0 eq.) at 23° C. The mixture is stirred at 23° C. for17 hours. The reaction mixture is carefully poured on a mixture ofsaturated aqueous solution of sodium thiosulphate and ice. The aqueouslayer is extracted with dichloromethane (3×30 cm³). The combined organiclayer is washed with brine, dried over magnesium sulphate, filtered offand concentrated to dryness. The crude product is purified by columnchromatography using petroleum ether (40-60° C.):dichloromethane mixture8:2 to afford title compound as a white solid (1.89 g, 66%).

¹³C NMR (101 MHz, CDCl₃): δ 158.09, 155.54, 151.15, 151.09, 150.27,129.33, 129.08, 115.40, 99.44, 99.18, 77.79, 77.48, 77.16.

¹⁹F NMR (376 MHz, CDCl₃): δ −96.58

Example 2

Compound S1-1 is prepared as follows.

5-Chloro-6-fluoro-4,7-bis-[4-(2-octyl-decyl)-thiophen-2-yl]-benzo[1,2,5]thiadiazole(S1)

A solution of 4,7-dibromo-5-chloro-6-fluoro-benzo[1,2,5]thiadiazole(1.00 g; 2.89 mmol; 1.00 eq.) andtributyl-[4-(2-octyl-decyl)-thiophen-2-yl]-stannane (4.51 g; 7.22 mmol;2.50 eq.) in anhydrous toluene (18 cm³) and anhydrous dimethylformamide(2 cm³) is degassed for 30 minutes with nitrogen.Tetrakis(triphenylphosphine)paladium(0) (166 mg; 0.140 mmol; 0.05 eq.)is added and the mixture is stirred at 120° C. for 18 hours. Thesolvents are removed under vacuum. The residue is purified by columnchromatography using petroleum ether (40-60° C.):dichloromethane mixture9:1 to afford the title compound as an orange oil (1.64 g, 66%).

¹H NMR (400 MHz, CDCl₃): δ 8.13 (s, 1H), 7.68 (d, J=1.4 Hz, 1H), 7.21(bd, J=5.1, 2H), 2.68 (d, J=6.7 Hz, 4H), 1.77-1.61 (m, 10H), 1.44-1.20(m, 64H), 0.92-0.85 (m, 12H).

Example 3

Monomer M2 is prepared as follows.

4,7-Bis-[5-bromo-4-(2-octyl-decyl)-thiophen-2-yl]-5-chloro-6-fluoro-benzo[1,2,5]thiadiazole(M2)

To a solution of5-chloro-6-fluoro-4,7-bis-[4-(2-octyl-decyl)-thiophen-2-yl]-benzo[1,2,5]thiadiazole(1.64 g; 1.92 mmol; 1.00 eq.) in a mixture of anhydrousdimethylformamide (20 cm³) and anhydrous chloroform (20 cm³) is added inone portion N-bromosuccinimide (751 mg; 4.22 mmol; 2.20 eq.) at 23° C.The mixture is stirred at 23° C. protected from light for 16 hours. Thereaction mixture is poured on water (100 cm³) and diluted with diethylether (50 cm³). The aqueous layer is extracted with diethyl ether (2×20cm³). The combined organic layer is washed with water, brine, dried overmagnesium sulphate, filtered off and concentrated to dryness. Theresidue is purified by column chromatography using petroleum ether(40-60° C.):dichloromethane mixture 10:1 to afford the title compound asan orange oil that slowly crystallizes at 23° C. (955 mg, 49%).

¹H NMR (400 MHz, CDCl₃): δ 7.98 (s, 1H), 7.67 (s, 1H), 2.62 (d, J=7.1Hz, 4H), 1.83-1.67 (m, 2H), 1.40-1.20 (m, 64H), 0.94-0.80 (m, 12H).

Example 4

Compound S1-2 is prepared as follows.

5-Chloro-4,7-bis-(4-dodecyl-thiophen-2-yl)-6-fluoro-benzo[1,2,5]thiadiazole(S2)

A solution of 4,7-dibromo-5-chloro-6-fluoro-benzo[1,2,5]thiadiazole (950mg; 2.74 mmol; 1.00 eq.) and tributyl-(4-dodecyl-thiophen-2-yl)-stannane(3.71 g; 6.03 mmol; 2.20 eq.) in a mixture of anhydrous toluene (50 cm³)and anhydrous DMF (10 cm³) is degassed with nitrogen for 30 minutes.Tetrakis(triphenylphosphine)palladium(0) (322 mg; 0.27 mmol; 0.10 eq.)is added and the mixture is heated at 110° C. for 5 days. After coolingto 23 C, methanol (50 cm³) is added. The obtained glue is collected byfiltration and is successively washed with methanol (50 cm³) and icecooled acetone (50 cm³). Filtration through a pad of silica(dichloromethane:petroleum ether (40-60° C.) mixture 1:1, followed byconcentration of sample in vacou affords the title compound as a yellowpowder (462 mg, 24%).

¹H NMR (400 MHz, Chloroform-d) δ 8.14 (d, J=1.2 Hz, 1H), 7.68 (d, J=1.5Hz, 1H), 7.23 (d, J=1.5 Hz, 1H), 7.21 (d, J=1.2 Hz, 1H), 2.72 (t, J=7.7Hz, 4H), 1.77-1.65 (m, 4H), 1.42-1.20 (m, 36H), 0.88 (t, J=6.7 Hz, 6H).

Example 5

Monomer M3 is prepared as follows.

4,7-Bis-(5-bromo-4-dodecyl-thiophen-2-yl)-5-chloro-6-fluoro-benzo[1,2,5]thiadiazole(M3)

To a solution of5-chloro-4,7-bis-(4-dodecyl-thiophen-2-yl)-6-fluoro-benzo[1,2,5]thiadiazole(462 mg; 0.67 mmol; 1.00 eq.) in chloroform (20 cm³) is added in oneportion N-bromosuccinimide (298 mg; 1.68 mmol; 2.50 eq.) at 23° C. Themixture is stirred at 23° C. protected from light for 60 hours. Themixture is poured on water and diluted with diethyl ether (30 cm³). Theaqueous layer is extracted with diethyl ether (2×10 cm³). The combinedorganic layer is washed with water, brine, dried over magnesiumsulphate, filtered off and concentrated to dryness. The residue isrecrystallized from refluxing 2-propanol (40 cm³) to afford the titlecompound as a red solid (350 mg, 61%).

¹H NMR (400 MHz, Chloroform-o) δ 7.99 (s, 1H), 7.68 (s, 1H), 2.67 (t,J=7.7 Hz, 4H), 1.72-1.61 (m, 4H), 1.45-1.21 (m, 36H), 0.87 (t, J=6.8 Hz,6H).

Example 6

Polymer P1 is prepared as follows.

4,7-Bis-[5-bromo-4-(2-octyl-dodecyl)-thiophen-2-yl]-5,6-difluoro-benzo[1,2,5]thiadiazole(113 mg; 0.11 mmol; 0.60 eq.),4,7-bis-[5-bromo-4-(2-octyl-dodecyl)-thiophen-2-yl]-5-chloro-6-fluoro-benzo[1,2,5]thiadiazole(77.00 mg; 0.07 mmol; 0.40 eq.),2,5-bis-trimethylstannanyl-thieno[3,2-b]thiophene (83.7 mg; 0.18 mmol;1.00 eq.), tris(dibenzylideneacetone) dipalladium(0) (3.3 mg; 3.59 μmol;0.05 eq.) and tri(o-tolyl)phosphine (4.4 mg; 0.01 mmol; 0.20 eq.) areplaced in a flask under nitrogen. Anhydrous toluene (20 cm³) is addedand the mixture is degassed for 10 minutes. The reaction mixture isheated to 90° C. and stirred at t his temperature for 15 minutes.Tributyl-phenyl-stannane (0.12 cm³; 0.36 mmol; 2.0 eq.) is then added,followed by an additional hour of stirring at 90° C. After addition ofbromo-benzene (0.19 cm³; 1.80 mmol; 10 eq.) the mixture is stirred for 1hour before the reaction mixture is poured into a flask with 150 cm³ ofmethanol.

The crude product is filtered off and washed with additional 10 cm³ ofmethanol. The polymer is sequentially extracted by soxhlet extractionusing acetone, petroleum ether (40-60° C.), cyclohexane, chloroform andchlorobenzene. The chlorobenzene fraction is concentrated under vacuum.Precipitation in methanol (20 cm³) and collection by filtration affords128 mg of the title polymer.

GPC (50° C., chlorobenzene): M_(n)=145 kDa. M_(w)=233 kDa PDI=1.61.

Example 7

Polymer P2 is prepared as follows.

4,7-bis-[5-bromo-4-(2-octyl-dodecyl)-thiophen-2-yl]-5,6-difluoro-benzo[1,2,5]thiadiazole(68.0 mg; 0.06 mmol; 0.30 eq.),4,7-bis-[5-bromo-4-(2-octyl-dodecyl)-thiophen-2-yl]-5-chloro-6-fluoro-benzo[1,2,5]thiadiazole(161 mg; 0.15 mmol; 0.70 eq.)2,5-bis-trimethylstannanyl-thieno[3,2-b]thiophene (100 mg; 0.21 mmol;1.00 eq.), tris(dibenzylideneacetone) dipalladium(0) (3.9 mg; 4.3 μmol;0.02 eq.) and tri(o-tolyl)phosphine (10.4 mg; 0.03 mmol; 0.16 eq.) areplaced in a flask under nitrogen. Anhydrous toluene (20 cm³) is addedand the mixture is degassed for 10 minutes. The reaction mixture isheated to 95° C. and stirred at t his temperature for 15 minutes.Tributyl-phenyl-stannane (0.21 cm³; 0.64 mmol; 3.00 eq.) is then addedand followed by an additional 50 minutes of stirring at 95° C. Afteraddition of bromobenzene (0.34 cm³; 3.22 mmol; 15.0 eq.), the mixture isstirred for 1 hour before the reaction mixture is poured into a flaskwith 150 cm³ of methanol.

The crude product is collected by filtration and washed with additional10 cm³ of methanol. The polymer is sequentially extracted by soxhletextraction using acetone, petroleum ether (40-60° C.), cyclohexane,chloroform and chlorobenzene. The chlorobenzene fraction is concentratedunder vacuum. Precipitation in methanol (20 cm³) and collection byfiltration affords 199 mg of the title polymer.

GPC (50° C., chlorobenzene): M_(n)=79.1 kDa. M_(w)=208 k Da. PDI=2.63.

Example 8

Polymer P3 is prepared as follows.

4,7-Bis-[5-bromo-4-(2-octyl-dodecyl)-thiophen-2-yl]-5-chloro-6-fluoro-benzo[1,2,5]thiadiazole(196 mg; 0.18 mmol; 1.00 eq.),2,5-bis-trimethylstannanyl-thieno[3,2-b]thiophene (85.3 mg; 0.18 mmol;1.00 eq.), tris(dibenzylideneacetone)dipalladium(0) (3.3 mg; 3.7 μmol;0.02 eq.) and tri(o-tolyl)phosphine (8.9 mg; 0.03 mmol; 0.16 eq.) areplaced in a flask under nitrogen. Anhydrous toluene (20 cm³) is addedand the mixture is degassed with nitrogen for 10 minutes. The reactionmixture is heated to 95° C. and stirred at this temperature for 15minutes. Tributyl-phenyl-stannane (0.18 cm³; 0.55 mmol; 3.0 eq.) is thenadded and the mixture is stirred at 95° C. for an additional hour. Afteraddition of bromobenzene (0.29 cm³; 2.75 mmol; 15.0 eq.) the mixture isstirred for 1 hour before the reaction mixture is poured into a flaskwith 100 cm³ of methanol.

The crude product is collected by filtration and washed with additional10 cm³ of methanol. The polymer is sequentially extracted by soxhletextraction using acetone, petroleum ether (40-60° C.), cyclohexane, andchloroform. The chloroform fraction is concentrated under vacuum.Precipitation in methanol (20 cm³) and collection by filtration affords199 mg of the title polymer.

GPC (50° C., chlorobenzene): M_(n)=62.4 kDa; M_(w)=155 kD a; PDI=2.49.

Example 9

Polymer P4 is prepared as follows.

A solution of4,7-Bis-[5-bromo-4-(2-octyl-dodecyl)-thiophen-2-yl]-5-chloro-6-fluoro-benzo[1,2,5]thiadiazole(191 mg; 0.18 mmol; 1.00 eq.),4,8-Bis-[5-(2-ethyl-hexyl)-thiophen-2-yl]-2,6-bis-trimethylstannanyl-benzo[1,2-b;4,5-b′]dithiophene(161 mg; 0.18 mmol; 1.00 eq.), tris(dibenzylideneacetone) dipalladium(0)(3.26 mg; 3.56 μmol; 0.02 eq.) and Tri(o-tolyl)phosphine (8.68 mg; 0.03mmol; 0.16 eq.) are placed in a flask under nitrogen. Anhydrous toluene(20 cm³) is added and the mixture is degassed with nitrogen for 10minutes. The reaction mixture is heated to 95° C. and stirred at thistemperature for 20 minutes. Tributyl-phenyl-stannane (0.17 cm³; 0.53mmol; 3.00 eq.) is then added and the mixture is stirred at 95° C. for 1more hour. Next bromobenzene (0.28 cm³; 2.67 mmol; 15.00 eq.) is addedand mixture is stirred for an additional hour. The reaction mixture isallowed to cool to 65° C. and precipitated into stir red methanol (100cm³).

The crude product is filtered off and washed with additional 10 cm³ ofmethanol. The polymer is sequentially extracted by soxhlet extractionusing acetone, petroleum ether (40-60° C.) and cyclohexane. Acetonefraction is discarded. The other fractions are concentrated undervacuum.

Precipitation in methanol (20 cm³) and collection by filtration affordsthe final polymer (165 mg).

GPC (50 CC, chlorobenzene): M_(n)=17.5 kDa; M_(w)=34.4 kDa; PDI=1.97.

Example 10

Polymer P5 is prepared as follows.

4,7-Bis-(5-bromo-4-dodecyl-thiophen-2-yl)-5-chloro-6-fluoro-benzo[1,2,5]thiadiazole(150 mg; 0.18 mmol; 1.00 eq.),4,8-Bis-[5-(2-ethyl-hexyl)-thiophen-2-yl]-2,6-bis-trimethylstannanyl-benzo[1,2-b;4,5-b′]dithiophene(160 mg; 0.18 mmol; 1.00 eq.), tris(dibenzylideneacetone) dipalladium(0)(3.24 mg; 3.54 μmol; 0.02 eq.) and tri(o-tolyl)phosphine (8.98 mg; 0.03mmol; 0.16 eq.) are placed in a flask under nitrogen. Anhydrous toluene(20 cm³) is added and the mixture is degassed with nitrogen for 10minutes. The reaction mixture is heated to 95° C. and stirred at thistemperature for 90 minutes. Tributyl-phenyl-stannane (0.17 cm³; 0.53mmol; 3.00 eq.) is then added and the reaction mixture is stirred at thesame temperature for 1 hour more. After addition of bromobenzene (0.28cm³; 2.66 mmol; 15.00 eq.) the mixture is stirred for 2 hour at 95° C.before the reaction mixture is poured into a flask with 100 cm³ ofmethanol.

The crude product is collected by filtration and washed with additional10 cm³ of methanol. The polymer is sequentially extracted by soxhletextraction using acetone, petroleum ether (40-60° C.), cyclohexane, andchloroform. Acetone and petroleum ether (40-60) fractions werediscarded. The other fractions are concentrated under vacuum.Precipitation in methanol (20 cm³) and collection by filtration toafford final polymer (171 mg).

GPC (50° C., chlorobenzene): M_(n)=18.7 kDa; PDI=1.71

Use Example A—OPV Device

Current-voltage characteristics are measured using a Keithley 2400 SMUwhile the solar cells are illuminated by a Newport Solar Simulator at100 mW-cm⁻² light. The solar simulator is equipped with AM1.5G filters.The illumination intensity is calibrated using a Si photodiode.

Power conversion efficiency is calculated using the following expression

$\eta = \frac{V_{oc} \times J_{sc} \times {FF}}{P_{in}}$

where FF is defined as

${FF} = \frac{V_{\max} \times J_{\max}}{V_{oc} \times J_{sc}}$

OPV devices are fabricated from solutions of one of the polymersaccording to the present invention and acceptor PCBM-C60 in organicsolvents. Details of the solution composition are shown in Table 1.

Organic photovoltaic (OPV) devices are fabricated on pre-patternedITO-glass substrates (13Ω/sq.) purchased from LUMTEC Corporation.Substrates are cleaned using common solvents (acetone, iso-propanol,deionized-water) in an ultrasonic bath. A layer of commerciallyavailable aluminium doped zinc oxide (AlZnO, Nanograde) is applied as auniform coating by doctor blade at 40° C. The AlZnO films are thenannealed at 100° C. for 10 minutes in air. Active material solution s(i.e. polymer+acceptor) are prepared to fully dissolve the solutes at a30 mg·cm⁻³ solution concentration. Thin films are blade-coated in airatmosphere to achieve active layer thicknesses between 50 and 800 nm asmeasured using a profilometer. A short drying period follows to ensureremoval of any residual solvent. Typically, blade-coated films are driedat 70 C for 2 minutes on a hotplate. On top of the active layer 0.1 mLof a conducting polymer poly(ethylene dioxythiophene) doped withpoly(styrene sulfonic acid) [PEDOT:PSS Clevios HTL Solar SCA 434(Heraeus)] was spread and uniformly coated by doctor blade at 70° C.Afterwards Ag (100 nm) cathodes are thermally evaporated through ashadow mask to define the cells. Table 2 shows the formulationcharacteristics of the individual photoactive material solutions,comprising a polymer as electron donor component and a fullerene or acompound according to the present invention as electron acceptorcomponent. Solutions 1-4 according to the present invention contain oneof polymers P1-P5 and fullerene PCBM-C60. The solvent is eithero-dichlorobenzene (oDCB), or a mixture of o-xylene with2,4-dimethylanisole (oXyl:DMA) in 75:25 ratio (v/v), or a mixture ofo-xylene with 1,8-diiodooctane (oXyl:DIO) in 98:2 ratio (v/v).

TABLE 2 Formulation characteristics Ratio Polymer: Concentration No.Polymer Fullerene g/L Solvent 1 P1 1.00:1.50 25 oXyl:DMA 2 P3 1.00:1.5025 oXyl:DMA 3 P4 1.00:1.50 25 oXyl:DIO 4 P5 1.00:1.50 25 oXyl:DIO

Table 3 shows the photovoltaic characteristics of cells fabricated asdescribed above.

TABLE 3 Photovoltaic cell characteristics under simulated solarirradiation at 1 sun (AM1.5G). Average Performance Voc Jsc FF PCE No. mVmA · cm⁻² % % 1 763 12.4 48 4.5 2 796  2.1 34 0.6 3 895  2.2 36 0.7 4726  5.3 37 1.4

Example 11

Molecular structures were optimized at B3LYP/6-31G* level using FireflyQC package (see Alex A. Granovsky, Firefly version 8, wwwhttp://classic.chem.msu.su/gran/firefly/index.htm), which is partiallybased on the GAMESS (US) source code (see M. W. Schmidt, K. K.Baldridge, J. A. Boatz, S. T. Elbert, M. S. Gordon, J. H. Jensen, S.Koseki, N. Matsunaga, K. A. Nguyen, S. Su, T. L. Windus, M. Dupuis, J.A. Montgomery J. Comput. Chem. 14, 1347-1363 (1993)).

E_(HOMO) and E_(LUMO) are defined as the eigenvalues of, respectively,the highest occupied and lowest unoccupied Kohn-Sham molecular orbitals,and are used as approximations of, respectively, ionisation potential(IP) and electron affinity (EA). E_(g) is defined as |E_(LUMO)−E_(HOMO)|and is the transport band gap of the material. S⁰-S¹ is the verticalexcitation energy from the ground state S⁰ to the first singlet excitedstate S¹, and is used as the measure of the optical band gap E_(g)(opt).

An approximate relation between E_(HOMO), E_(LUMO) and E_(g) of donorand acceptor materials in a bulk-heterojunction is known as the Scharbermodel [M. C. Scharber, D. Muhlbacher, M. Koppe, P. Denk, C. Waldauf, A.J. Heeger, C. J. Brabec, Adv. Mater. 2006, 18, 789-794]. It is widelyaccepted that when the donor material of the donor-acceptor blendabsorbs light and forms an excited state, the excited electron must hoponto the neighbouring acceptor site in order for the free carriers to beformed. The driving force of this process is the energetic differencebetween the excited state of the donor material and the electronaffinity (approximated by E_(LUMO)) of the acceptor material and hasbeen empirically found to be at least ca. 0.35 eV for charge generationto be efficient [D. Veldman, S. C. J. Meskers, R. A. J. Janssen, Adv.Funct. Mater. 2009, 19, 1939-1948; M. C. Scharber, N. S. Sariciftci,Progr. Polym. Sci. 38 (2013) 1929-1940]. Therefore, tuning of acceptor'sE_(LUMO) is of paramount importance, lowering its value will increasethe driving force for charge generation and may allow usinglower-bandgap donor material, whilst increasing E_(LUMO) may hindercharge generation. For the present OSC materials, owing to their smalloptical band gap, another mechanism is also possible: light absorptionby the acceptor followed by hole injection to the donor material, drivenby the energy difference between E_(HOMO) of donor and acceptor,respectively [W. Zhao, D. Qian, S. Zhang, S. Li, O. Inganäs, F. Gao, J.Hou, Adv. Mater. 2016, DOI: 10.1002/adma.201600281]. This mechanism isresponsible for non-negligible external quantum efficiency beyond theabsorption edge of the donor material, and retaining of this advantageof the acceptor material requires careful tuning of HOMO energy. Theresults are shown in Table 1.

No Structure E_(HOMO)* E_(LUMO)* E_(g)* S⁰-S¹* S2-1

−5.17 −3.39 1.75 1.97 S2-2

−5.06 −3.34 1.74 1.98 S2-3

−4.86 −2.88 2.23 1.90 S2-4

−4.93 −2.82 2.24 1.87 S1-5

−5.3  −3.36 2.63 1.81 *in eV

1. A compound comprising a unit of formula I

wherein the individual radicals, independently of each other and on eachoccurrence identically or differently, have the following meanings oneof X¹ and X² is F and the other of X¹ and X² is Cl, U is NR, O, S, Se orTe, R is H or linear, branched or cyclic alkyl with 1 to 30 C atoms, inwhich one or more CH₂ groups are optionally replaced by —O—, —S—,—C(═O)—, —C(═S)—, —C(═O)—O—, —O—C(═O)—, —NR⁰—, —SiR⁰R⁰⁰—, —CF₂—,—CR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— in such a manner that O and/or S atomsare not linked directly to one another, and in which one or more H atomsare optionally replaced by F, Cl, Br, I or CN, Y¹, Y² are, eachindependently, F, Cl or CN, R⁰, R⁰⁰ are, each independently, H or linearor branched alkyl with 1 to 20 atoms that is optionally fluorinated,with the proviso that the following compounds are excluded

wherein X¹, X² and U are as defined above, A and B denote H or F, or oneof A and B denotes F and the other denotes Cl.
 2. The compound accordingto claim 1, which is a conjugated polymer comprising one or morerepeating units of formula I and one or more arylene or heteroaryleneunits that have from 5 to 20 ring atoms, are mono- or polycyclic,optionally contains fused rings, and are unsubstituted or substituted byone or more identical or different groups L, wherein L is F, Cl, —CN,—NC, —NCO, —NCS, —OCN, —SCN, —R⁰, —OR⁰, —SR⁰, —C(═O)X⁰, —C(═O)R⁰,—C(═O)—OR⁰, —O—C(═O)—R⁰, —NH₂, —NHR⁰, —NR⁰R⁰⁰, —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰,—SO₃R⁰, —SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, or optionally substituted silyl,or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionallysubstituted and optionally comprises one or more hetero atoms, whereinX⁰ is halogen and R⁰, R⁰⁰ are, each independently, H or linear orbranched alkyl with 1 to 20 atoms that is optionally fluorinated.
 3. Thecompound according to claim 1, which is a conjugated polymer comprisingone or more repeating units of formula II1 or II2, and optionally one ormore repeating units of formula II3:—(Ar¹)_(a)—U—(Ar²)_(b)—(Ar³)_(c)—(Ar⁴)_(d)—  II1—(Ar¹)_(a)—(Ar²)_(b)—U—(Ar³)_(c)—(Ar⁴)_(d)—  II2—(Ar¹)_(a)—(Ar²)_(b)—(Ar³)_(c)—(Ar⁴)—  II3 wherein the individualradicals, independently of each other and on each occurrence identicallyor differently, have the following meanings U is a unit of formula I,Ar¹⁻⁴ are, each independently, arylene or heteroarylene that has 5 to 20ring atoms, is mono- or polycyclic, does optionally contain fused rings,is unsubstituted or substituted by one or more identical or differentgroups R^(S), and is different from formula I, or CY¹═CY²— or —C≡C—,R^(S) is F, Cl, CN, or linear, branched or cyclic alkyl with 1 to 30 Catoms, in which one or more CH₂ groups are optionally replaced by —O—,—S—, —C(═O)—, —C(═S)—, —C(═O)—O—, —O—C(═O)—, —NR⁰—, —SiR⁰R⁰⁰—, —CF₂—,—CR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— in such a manner that O and/or S atomsare not linked directly to one another, and in which one or more H atomsare optionally replaced by F, Cl, Br, I or CN, and in which one or moreCH₂ or CH₃ groups are optionally replaced by a cationic or anionicgroup, or R^(S) is aryl, heteroaryl, arylalkyl, heteroarylalkyl, aryloxyor heteroaryloxy, wherein each of the aforementioned cyclic groups has 5to 20 ring atoms, is mono- or polycyclic, does optionally contain fusedrings, and is unsubstituted or substituted by one or more identical ordifferent groups L, L is F, Cl, —CN, —NC, —NCO, —NCS, —OCN, —SCN, —R⁰,—OR⁰, —SR⁰, —C(═O)X⁰, —C(═O)R⁰, —C(═O)—OR⁰, —O—C(═O)—R⁰, —NH₂, —NHR⁰,—NR⁰R⁰⁰, —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰, —SO₃R⁰, —SO₂R⁰, —OH, —NO₂, —CF₃,—SF₅, or optionally substituted silyl, or carbyl or hydrocarbyl with 1to 30 C atoms that is optionally substituted and optionally comprisesone or more hetero atoms, wherein X⁰ is halogen, Y¹, Y² are, eachindependently, H, F, Cl or CN, R⁰, R⁰⁰ are, each independently, H orlinear or branched alkyl with 1 to 20 atoms that is optionallyfluorinated, a, b, c, d are, each independently, 0 or 1, wherein informula II3 a+b+c+d≥1.
 4. The compound according to claim 1, which is aconjugated polymer comprising one or more repeating units selected fromformula U1-U4 and one or more repeating units selected from formulaeU5-U7-(A)-  U1-(A-Sp)-  U2-(A-D)-  U3—(Sp-A-Sp)-  U4-(D)-  U5-(D-Sp)-  U6—(Sp-D-Sp)-  U7 wherein D denotes a donor unit, A denotes an acceptorunit and Sp denotes a spacer unit, all of which are, independently ofeach other and on each occurrence identically or differently, selectedfrom arylene or heteroarylene that has from 5 to 20 ring atoms, is mono-or polycyclic, optionally contains fused rings, are is unsubstituted orsubstituted by one or more identical or different groups L, and and thepolymer contains at least one repeating unit of formulae U1-U4 wherein Ais a unit of formula I, and wherein L is F, Cl, —CN, —NC, —NCO, —NCS,—OCN, —SCN, —R⁰, —OR⁰, —SR⁰, —C(═O)X⁰, —C(═O)R⁰, —C(═O)—OR⁰,—O—C(═O)—R⁰, —NH₂, —NHR⁰, —NR⁰R⁰⁰, —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰, —SO₃R⁰,—SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, or optionally substituted silyl, orcarbyl or hydrocarbyl with 1 to 30 C atoms that is optionallysubstituted and optionally comprises one or more hetero atoms, whereinX⁰ is halogen, and R⁰, R⁰⁰ are, each independently, H or linear orbranched alkyl with 1 to 20 atoms that is optionally fluorinated.
 5. Thecompound according to claim 1, which is a conjugated polymer selectedfrom the following formulae-[(D-Sp)_(x)-(A-Sp)_(y)]_(n)-  Pi-[(A-D)_(x)-(A-Sp)_(y)]_(n)-  Pi-[(D)_(x)-(Sp-A-Sp)_(y)]_(n)-  Piii-[D-Sp-A-Sp]_(n)-  Piv-[D-A]_(n)-  Pv-[D-Sp-A-Sp]_(n)  Pvi-[D¹-A-D²-A]_(n)  Pvii-[D-A¹-D-A²]_(n)  Pviii wherein D denotes a donor unit, A denotes anacceptor unit and Sp denotes a spacer unit, all of which are,independently of each other and on each occurrence identically ordifferently, from arylene or heteroarylene that has from 5 to 20 ringatoms, is mono- or polycyclic, optionally contains fused rings, are isunsubstituted or substituted by one or more identical or differentgroups L, A and D can each, in case of multiple occurrence, also havedifferent meanings, D¹ and D² have one of the meanings given for D andare different from each other, A¹ and A² have one of the meanings givenfor A and are different from each other, x and y are each, independentlyof one another, a non-integer>0 and <1, with x+y=1, and n is aninteger>1, and wherein L is F, Cl, —CN, —NC, —NCO, —NCS, —OCN, —SCN,—R⁰, —OR⁰, —SR⁰, —C(═O)X⁰, —C(═O)R⁰, —C(═O)—OR⁰, —O—C(═O)—R⁰, —NH₂,—NHR⁰, —NR⁰R⁰⁰, —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰, —SO₃R⁰, —SO₂R⁰, —OH, —NO₂,—CF₃, —SF₅, or optionally substituted silyl, or carbyl or hydrocarbylwith 1 to 30 C atoms that is optionally substituted and optionallycomprises one or more hetero atoms, wherein X⁰ is halogen, and R⁰, R⁰⁰are, each independently, H or linear or branched alkyl with 1 to 20atoms that is optionally fluorinated.
 6. The compound according to claim1, which is a conjugated polymer selected from the following formulae

wherein R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ independently of eachother, and on each occurrence identically or differently, denote H orhave one of the meanings of L, L is F, Cl, —CN, —NC, —NCO, —NCS, —OCN,—SCN, —R⁰, —OR⁰, —SR⁰, —C(═O)X⁰, —C(═O)R⁰, —C(═O)—OR⁰, —O—C(═O)—R⁰,—NH₂, —NHR⁰, —NR⁰R⁰⁰, —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰, —SO₃R⁰, —SO₂R⁰, —OH,—NO₂, —CF₃, —SF₅, or optionally substituted silyl, or carbyl orhydrocarbyl with 1 to 30 C atoms that is optionally substituted andoptionally comprises one or more hetero atoms, wherein X⁰ is halogen,and R⁰, R⁰⁰ are, each independently, H or linear or branched alkyl with1 to 20 atoms that is optionally fluorinated, x and y are each,independently of one another, a non-integer>0 and <1, with x+y=1, and nis an integer>1, w and z have one of the meanings given for y,x+y+w+z=1, a, b, c and d are independently of each other 0 or 1, one ofX¹ and X² is F and the other of X¹ and X² is Cl, one of X³ and X⁴ is Fand the other is Cl, and X¹¹, X¹², X¹³ and X¹⁴ denote independently ofeach other H, F or Cl, or a polymer comprising one or more repeatingunits selected from formulae P1-P34 wherein n is
 1. 7. The compoundaccording to claim 6, wherein in the formulae P1-P34 R¹¹⁻¹⁶, when beingdifferent from H, are selected from the following groups: a) the groupconsisting of linear or branched alkyl, alkoxy or sulfanylalkyl with 1to 30 C atoms that is optionally fluorinated, b) the group consisting oflinear or branched alkylcarbonyl or alkylcarbonyloxy with 2 to 30 Catoms, that is optionally fluorinated, and R¹⁷ and R¹⁸, when beingdifferent from H, are selected from groups a) or b) above or from F orCl.
 8. The compound according to claim 1, which is a small molecule oroligomer of formula S1 or S2R^(T1)—(Ar¹¹)_(a1)—[(Ar¹³)_(c1)—U—(Ar¹⁴)_(d1)—]_(e1)(Ar¹²)_(b1)—R^(T2)  S1R^(T1)—(Ar²¹)_(a2)—(Ar²³)_(c2)-[(core1)_(f2)—(Ar²⁵)_(e2)-(core2)_(g2)]_(h2)—(Ar²⁴)_(d2)—(Ar²²)_(b2)—R^(T2)  S2wherein the individual radicals, independently of each other and on eachoccurrence identically or differently, have the following meanings U isa unit of formula I, Ar¹¹⁻¹⁴ are, each independently, arylene orheteroarylene that has from 5 to 20 ring atoms, is mono- or polycyclic,optionally contains fused rings, and is unsubstituted or substituted byone or more identical or different groups R¹, or —CY¹═CY²— or —C≡C—,Ar²¹⁻²⁵ are, each independently, arylene or heteroarylene that has from5 to 20 ring atoms, is mono- or polycyclic, optionally contains fusedrings, and is unsubstituted or substituted by one or more identical ordifferent groups R¹, or —CY¹═CY²— or —C≡C—, wherein at least one ofAr²¹⁻²⁵ denotes U, core1, core2, are, each independently, polycyclic,fused arylene or heteroarylene that has from 8 to 30 ring atoms, and isunsubstituted or substituted by one or more identical or differentgroups R¹, R¹ is H, F, Cl, CN, or straight-chain, branched or cyclicalkyl with 1 to 30, preferably 1 to 20, C atoms, in which one or moreCH₂ groups are optionally replaced by —O—, —S—, —C(═O)—, —C(═S)—,—C(═O)—O—, —O—C(═O)—, —NR⁰—, —SiR⁰R⁰⁰—, —CF₂—, —CR⁰═CR⁰⁰—, —CY¹═CY²— or—C≡C— in such a manner that O and/or S atoms are not linked directly toone another, and in which one or more H atoms are optionally replaced byF, Cl, Br, I or CN, and in which one or more CH₂ or CH₃ groups areoptionally replaced by a cationic or anionic group, or aryl, heteroaryl,arylalkyl, heteroarylalkyl, aryloxy or heteroaryloxy, wherein each ofthe aforementioned cyclic groups has 5 to 20 ring atoms, is mono- orpolycyclic, does optionally contain fused rings, and is unsubstituted orsubstituted by one or more identical or different groups L, L is F, Cl,—CN, —NC, —NCO, —NCS, —OCN, —SCN, —R⁰, —OR⁰, —SR⁰, —C(═O)X⁰, —C(═O)R⁰,—C(═O)—OR⁰, —O—C(═O)—R⁰, —NH₂, —NHR⁰, —NR⁰R⁰⁰, —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰,—SO₃R⁰, —SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, or optionally substituted silyl,or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionallysubstituted and optionally comprises one or more hetero atoms, whereinX⁰ is halogen, Y¹, Y² are, each independently, H, F, Cl or CN, R⁰, R⁰⁰are, each independently, H or linear or branched alkyl with 1 to 20,preferably 1 to 12, C atoms that is optionally fluorinated, R^(T1),R^(T2) are, each independently, H, F, Cl, Br, —NO₂, or a carbyl orhydrocarbyl group with 1 to 30 C atoms that is optionally substituted byone or more groups L and optionally comprises one or more hetero atoms,and wherein in formula S2 preferably at least one of R^(T1) and R^(T2)is H or an electron withdrawing group, a1-d1 are, each independently, 0,1, 2 or 3, preferably with at least one of a1-d1 being ≥1, e1 is 1, 2 or3, a2-e2 are, each independently, 0, 1, 2 or 3, with at least one of a2,b2, c2 and d2 being ≥1, f2 is 1, 2 or 3, g2 is 0, 1, 2 or 3, h is 1, 2or
 3. 9. The compound according to claim 8, wherein R^(T1) and R^(T2)are each independently selected from H, F, Cl, Br, —NO₂, —CN, —CF₃, R*,—CF₂—R*, —O—R*, —S—R*, —SO₂—R*, —SO₃—R*, —C(═O)—H, —C(═O)—R*, —C(═S)—R*,—C(═O)—CF₂—R*, —C(═O)—OR*, —C(═S)—OR*, —O—C(═O)—R*, —O—C(═S)—R*,—C(═O)—SR*, —S—C(═O)—R*, —C(═O)NR*R**, —NR*—C(═O)—R*, —NHR*, —NR*R**,—CR*═CR*R**, —C≡C—R*, —C≡C—SiR*R**R***, —SiR*R**R***, —CH═CH(CN),—CH═C(CN)₂, —C(CN)═C(CN)₂, —CH═C(CN)(R^(a)), CH═C(CN)—C(═O)—OR*,—CH═C(CO—OR*)₂, —CH═C(CO—NR*R**)₂, and the group consisting of thefollowing formulae

wherein the individual radicals, independently of each other and on eachoccurrence identically or differently, have the following meaningsR^(a), R^(b) are, each independently, aryl or heteroaryl, each havingfrom 4 to 30, preferably from 5 to 20, ring atoms, optionally containingfused rings and being unsubstituted or substituted with one or moregroups L, or one of the meanings given for L, R*, R**, R***, are, eachindependently, alkyl with 1 to 20 C atoms which is straight-chain,branched or cyclic, and is unsubstituted, or substituted with one ormore F or Cl atoms or CN groups, or perfluorinated, and in which one ormore C atoms are optionally replaced by —O—, —S—, —C(═O)—, —C(═S)—,—SiR⁰R⁰⁰—, —NR⁰R⁰⁰—, —CHR⁰═CR⁰⁰— or —C≡C— such that O- and/or S-atomsare not directly linked to each other, L is F, Cl, —NO₂, —CN, —NC, —NCO,—NCS, —OCN, —SCN, R⁰, OR⁰, SR⁰, —C(═O)X₀, —C(═O)R⁰, —C(═O)—OR⁰,—O—C(═O)—R⁰, —NH₂, —NHR⁰, —NR⁰R⁰⁰, —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰, —SO₃R⁰,—SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, or optionally substituted silyl, orcarbyl or hydrocarbyl with 1 to 30, preferably 1 to 20 C atoms that isoptionally substituted and optionally comprises one or more heteroatoms, preferably F, —CN, R⁰, —OR⁰, —SR⁰, —C(═O)—R⁰, —C(═O)—OR⁰,—O—C(═O)—R⁰, —O—C(═O)—OR⁰, —C(═O)—NHR⁰, —C(═O)—NR⁰R⁰⁰, L′ is H or one ofthe meanings of L, R⁰, R⁰⁰ are, each independently, H or straight-chainor branched alkyl with 1 to 20, preferably 1 to 12 C atoms that isoptionally fluorinated, Y¹, Y² are, each independently, H, F, Cl or CN,X⁰ is halogen, preferably F or Cl, r is 0, 1, 2, 3 or 4, s is 0, 1, 2,3, 4 or 5, t is 0, 1, 2 or 3, u is 0, 1 or 2, and wherein preferably atleast one of R^(T1) and R^(T2) denotes H or an electron withdrawinggroup.
 10. The compound according to claim 8, wherein both of R^(T1) andR^(T2) denote an electron withdrawing group, or both of R^(T1) andR^(T2) denote H.
 11. The compound according to claim 9, wherein R^(T1)and R^(T2), when denoting an electron withdrawing group, are eachindependently selected from —CN, —C(═O)—OR*, —C(═S)—OR*, —CH═CH(CN),—CH═C(CN)₂, —C(CN)═C(CN)₂, —CH═C(CN)(R^(a)), CH═C(CN)—C(═O)—OR*,—CH═C(CO—OR*)₂, and formulae T1-T60.
 12. The compound according to claim9, wherein R^(T1) and R^(T2), when denoting an electron withdrawinggroup, are each independently selected from formulae T10, T36, T37, T38,T39, T47 and T52.
 13. The compound according to claim 8, which isselected of formula S1 wherein Ar¹⁻⁸ are selected from the followinggroups a) the group consisting of the formulae D1-D151, very preferablyof the formulae D1, D7, D10, D11, D19, D22, D29, D30, D35, D36, D37,D44, D55, D84, D87, D88, D89, D93, D94, D106, D111, D139, D140, D141,D146 and D150, b) the group consisting of the formulae A1-A103, verypreferably of the formulae A1, A6, A7, A15, A16, A20, A36, A74, A84,A88, A92, A94, A98 and A103, c) the group consisting of the formulaeSp1-Sp18, very preferably of the formulae Sp1, Sp2, Sp6, Sp10, Sp11,Sp12, Sp13 and Sp14.
 14. The compound according to claim 8, which isselected of formula S2 wherein those of Ar²¹⁻²⁵ that are not a unit offormula I are each independently and on each occurrence identically ordifferently selected from the following formulae and their mirrorimages:

wherein X²¹, X²², X²³ and X²⁴ denote H, F, Cl, —CN, R⁰, OR⁰ or C(═O)OR⁰,and R⁰ is H or straight-chain or branched alkyl with 1 to 20, preferably1 to 12 C atoms that is optionally fluorinated, and wherein in formulaAR6 those groups are excluded wherein one of X²¹ and X²² is F and theother of X²¹ and X²² is Cl.
 15. The compound according to claim 8, whichis selected of formula S2 wherein core1 and core2 are independently ofeach other, and on each occurrence identically or differently, selectedfrom the following subformulae

wherein R¹ is H, F, Cl, CN, or straight-chain, branched or cyclic alkylwith 1 to 30, preferably 1 to 20, C atoms, in which one or more CH₂groups are optionally replaced by —O—, —S—, —C(═O)—, —C(═S)—, —C(═O)—O—,—O—C(═O)—, —NR⁰—, —SiR⁰R⁰⁰—, —CF₂—, —CR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— insuch a manner that O and/or S atoms are not linked directly to oneanother, and in which one or more H atoms are optionally replaced by F,Cl, Br, I or CN, and in which one or more CH₂ or CH₃ groups areoptionally replaced by a cationic or anionic group, or aryl, heteroaryl,arylalkyl, heteroarylalkyl, aryloxy or heteroaryloxy, wherein each ofthe aforementioned cyclic groups has 5 to 20 ring atoms, is mono- orpolycyclic, does optionally contain fused rings, and is unsubstituted orsubstituted by one or more identical or different groups L, L is F, Cl,—CN, —NC, —NCO, —NCS, —OCN, —SCN, —R⁰, —OR⁰, —SR⁰, —C(═O)X⁰, —C(═O)R⁰,—C(═O)—OR⁰, —O—C(═O)—R⁰, —NH₂, —NHR⁰, —NR⁰R⁰⁰, —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰,—SO₃R⁰, —SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, or optionally substituted silyl,or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionallysubstituted and optionally comprises one or more hetero atoms, whereinX⁰ is halogen, R⁰, R⁰⁰ are, each independently, H or linear or branchedalkyl with 1 to 20, preferably 1 to 12, C atoms that is optionallyfluorinated, and R²⁻¹⁰, independently of each other and on eachoccurrence identically or differently, have one of the meanings givenfor R¹, and the pair of R¹ and R², and/or the pair of R³ and R⁴,together with the C atom to which they are attached, may also form aspiro group with 5 to 20 ring atoms which is mono- or polycyclic,optionally contains fused rings, and is unsubstituted or substituted byone or more identical or different groups L.
 16. The compound accordingto claim 8, which is selected of formula S2AR^(T1)—(Ar²¹)_(a2)-core1-(Ar²²)_(b2)—R^(T2)  S2A wherein R^(T1), R^(T2),core1, Ar²¹, Ar²², a2 and b2 are as defined above, and “core1” ispreferably selected from formulae C1-C26 as defined above.
 17. Thecompound according claim 8, which is selected from the followinggroups: 1) The group consisting of compounds of formula S2 and S2A,wherein core1 is selected from formulae C1-C26, Ar²¹ and Ar²² are eachindependently selected from formula I, a2 and b2 are each independently1 or 2, and R^(T1) and R^(T2) are selected from formula T10; 2) Thegroup consisting of compounds of formula S2 and S2A, wherein core1 isselected from formulae C1-C26, Ar²¹ and Ar²² are each independentlyselected from formula I, a2 and b2 are each independently 1 or 2, andR^(T1) and R^(T2) are selected from formula T36; 3) The group consistingof compounds of formula S2 and S2A, wherein core1 is selected fromformulae C1-C26, Ar²¹ and Ar²² are each independently selected fromformula I, a2 and b2 are each independently 1 or 2, and R^(T1) andR^(T2) are selected from formula T37; 4) The group consisting ofcompounds of formula S2 and S2A, wherein core1 is selected from formulaeC1-C26, Ar²¹ and Ar²² are each independently selected from formula I, a2and b2 are each independently 1 or 2, and R^(T1) and R^(T2) are selectedfrom formula T38; 5) The group consisting of compounds of formula S2 andS2A, wherein core1 is selected from formulae C1-C26, Ar²¹ and Ar²² areeach independently selected from formula I, a2 and b2 are eachindependently 1 or 2, and R^(T1) and R^(T2) are selected from formulaT39; 6) The group consisting of compounds of formula S2 and S2A, whereincore1 is selected from formulae C1-C26, Ar²¹ and Ar²² are eachindependently selected from formula I, a2 and b2 are each independently1 or 2, and R^(T1) and R^(T2) are selected from formula T47; 7) Thegroup consisting of compounds of formula S2 and S2A, wherein core1 isselected from formulae C1-C26, Ar²¹ and Ar²² are each independentlyselected from formula I, a2 and b2 are each independently 1 or 2, andR^(T1) and R^(T2) are selected from formula T52; 8) The group consistingof compounds of formula S2 and S2A, wherein core1 is selected fromformulae C1-C26, Ar²¹ and Ar²² are each independently selected fromformula I, a2 and b2 are each independently 1 or 2, and R^(T1) andR^(T2) denote H.
 18. The compound according to claim 1, which is amonomer of formula M1 or M2R²³—(Ar¹)_(a)—U—(Ar²)_(b)—(Ar³)_(c)—(Ar⁴)_(a)—R²⁴  M1R²³—(Ar¹)_(a)—(Ar²)_(b)—U—(Ar³)_(c)—(Ar⁴)_(a)—R²⁴  M2 wherein U is aunit of formula I, Ar¹⁻⁴ are, each independently, arylene orheteroarylene that has 5 to 20 ring atoms, is mono- or polycyclic, doesoptionally contain fused rings, is unsubstituted or substituted by oneor more identical or different groups R^(S), and is different fromformula I, or CY¹═CY²— or —C≡C—, R^(S) F, Cl, CN, or linear, branched orcyclic alkyl with 1 to 30 C atoms, in which one or more CH₂ groups areoptionally replaced by —O—, —S—, —C(═O)—, —C(═S)—, —C(═O)—O—, —O—C(═O)—,—NR⁰—, —SiR⁰R⁰⁰—, —CF₂—, —CR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— in such a mannerthat O and/or S atoms are not linked directly to one another, and inwhich one or more H atoms are optionally replaced by F, Cl, Br, I or CN,and in which one or more CH₂ or CH₃ groups are optionally replaced by acationic or anionic group, or R^(S) is aryl, heteroaryl, arylalkyl,heteroarylalkyl, aryloxy or heteroaryloxy, wherein each of theaforementioned cyclic groups has 5 to 20 ring atoms, is mono- orpolycyclic, does optionally contain fused rings, and is unsubstituted orsubstituted by one or more identical or different groups L, L is F, Cl,—CN, —NC, —NCO, —NCS, —OCN, —SCN, —R⁰, —OR⁰, —SR⁰, —C(═O)X⁰, —C(═O)R⁰,—C(═O)—OR⁰, —O—C(═O)—R⁰, —NH₂, —NHR⁰, —NR⁰R⁰⁰, —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰,—SO₃R⁰, —SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, or optionally substituted silyl,or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionallysubstituted and optionally comprises one or more hetero atoms, Y¹, Y²are, each independently, H, F, Cl or CN, R⁰, R⁰⁰ are, eachindependently, H or linear or branched alkyl with 1 to 20 atoms that isoptionally fluorinated, a, b, c, d are, each independently, 0 or 1, andR²³ and R²⁴ are independently of each other selected from the groupconsisting of an activated C—H bond, Cl, Br, I, O-tosylate, O-triflate,O-mesylate, O-nonaflate, —SiMe₂F, —SiMeF₂, —O—SO₂Z¹, —B(OZ²)₂,—CZ³═C(Z³)₂, —C≡CH, —C≡CSi(Z¹)₃, —ZnX⁰ and —Sn(Z⁴)₃, wherein X⁰ ishalogen, Z¹⁻⁴ are selected from the group consisting of alkyl and aryl,each being optionally substituted, and two groups Z² may also form acycloboronate group having 2 to 20 C atoms together with the B- andO-atoms.
 19. The compound according to claim 18, which is selected fromthe following formulaeR²³—U—R²⁴  M1aR²³—Sp-U-Sp-R²⁴  M1 bR²³-Sp-U—R²⁴  M1cR²³—U-D-R²⁴  M1d wherein U is a unit of formula I, Ar²³⁻²⁴ are, eachindependently, arylene or heteroarylene that has 5 to 20 ring atoms, ismono- or polycyclic, optionally contains fused rings, and isunsubstituted or substituted by one or more identical or differentgroups R¹, or CY¹═CY²— or —C≡C—, wherein preferably R²³ and R²⁴ areindependently of each other selected from the group consisting of anactivated C—H bond, Cl, Br, I, O-tosylate, O-triflate, O-mesylate,O-nonaflate, —SiMe₂F, —SiMeF₂, —O—SO₂Z¹, —B(OZ²)₂, —CZ³═C(Z³)₂, —C≡CH,—C≡CSi(Z¹)₃, —ZnX⁰ and —Sn(Z⁴)₃, wherein X⁰ is halogen, Z¹⁻⁴ areselected from the group consisting of alkyl and aryl, each beingoptionally substituted, and two groups Z² may also form a cycloboronategroup having 2 to 20 C atoms together with the B- and O-atoms R¹ is H,F, Cl, CN, or straight-chain, branched or cyclic alkyl with 1 to 30,preferably 1 to 20, C atoms, in which one or more CH₂ groups areoptionally replaced by —O—, —S—, —C(═O)—, —C(═S)—, —C(═O)—O—, —O—C(═O)—,—NR⁰—, —SiR⁰R⁰⁰—, —CF₂—, —CR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— in such a mannerthat O and/or S atoms are not linked directly to one another, and inwhich one or more H atoms are optionally replaced by F, Cl, Br, I or CN,and in which one or more CH₂ or CH₃ groups are optionally replaced by acationic or anionic group, or aryl, heteroaryl, arylalkyl,heteroarylalkyl, aryloxy or heteroaryloxy, wherein each of theaforementioned cyclic groups has 5 to 20 ring atoms, is mono- orpolycyclic, does optionally contain fused rings, and is unsubstituted orsubstituted by one or more identical or different groups L, L is F, Cl,—CN, —NC, —NCO, —NCS, —OCN, —SCN, —R⁰, —OR⁰, —SR⁰, —C(═O)X⁰, —C(═O)R⁰,—C(═O)—OR⁰, —O—C(═O)—R⁰, —NH₂, —NHR⁰, —NR⁰R⁰⁰, —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰,—SO₃R⁰, —SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, or optionally substituted silyl,or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionallysubstituted and optionally comprises one or more hetero atoms, whereinX⁰ is halogen, Y¹, Y² are, each independently, H, F, Cl or CN, R⁰, R⁰⁰are, each independently, H or linear or branched alkyl with 1 to 20,preferably 1 to 12, C atoms that is optionally fluorinated, D denotes adonor unit, and Sp denotes a spacer unit, all of which are,independently of each other and on each occurrence identically ordifferently, from arylene or heteroarylene that has from 5 to 20 ringatoms, is mono- or polycyclic, optionally contains fused rings, are isunsubstituted or substituted by one or more identical or differentgroups L.
 20. A process of preparing a conjugated polymer according toclaim 2, comprising copolymerising one or more monomers of formula M1,M2R²³—(Ar¹)_(a)—U—(Ar²)_(b)—(Ar³)_(c)—(Ar⁴)_(a)—R²⁴  M1R²³—(Ar¹)_(a)—(Ar²)_(b)—U—(Ar³)_(c)—(Ar⁴)_(a)—R²⁴  M2 wherein U is aunit of formula I, Ar¹⁻⁴ are, each independently, arylene orheteroarylene that has 5 to 20 ring atoms, is mono- or polycyclic, doesoptionally contain fused rings, is unsubstituted or substituted by oneor more identical or different groups R^(S), and is different fromformula I, or CY¹═CY²— or —C≡C—, R^(S) F, Cl, CN, or linear, branched orcyclic alkyl with 1 to 30 C atoms, in which one or more CH₂ groups areoptionally replaced by —O—, —S—, —C(═O)—, —C(═S)—, —C(═O)—O—, —O—C(═O)—,—NR⁰—, —SiR⁰R⁰⁰—, —CF₂—, —CR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— in such a mannerthat O and/or S atoms are not linked directly to one another, and inwhich one or more H atoms are optionally replaced by F, Cl, Br, I or CN,and in which one or more CH₂ or CH₃ groups are optionally replaced by acationic or anionic group, or R^(S) is aryl, heteroaryl, arylalkyl,heteroarylalkyl, aryloxy or heteroaryloxy, wherein each of theaforementioned cyclic groups has 5 to 20 ring atoms, is mono- orpolycyclic, does optionally contain fused rings, and is unsubstituted orsubstituted by one or more identical or different groups L, L is F, Cl,—CN, —NC, —NCO, —NCS, —OCN, —SCN, —R⁰, —OR⁰, —SR⁰, —C(═O)X⁰, —C(═O)R⁰,—C(═O)—OR⁰, —O—C(═O)—R⁰, —NH₂, —NHR⁰, —NR⁰R⁰⁰, —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰,—SO₃R⁰, —SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, or optionally substituted silyl,or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionallysubstituted and optionally comprises one or more hetero atoms, Y¹, Y²are, each independently, H, F, Cl or CN, R⁰, R⁰⁰ are, eachindependently, H or linear or branched alkyl with 1 to 20 atoms that isoptionally fluorinated, a, b, c, d are, each independently, 0 or 1, andR²³ and R²⁴ are independently of each other selected from the groupconsisting of an activated C—H bond, Cl, Br, I, O-tosylate, O-triflate,O-mesylate, O-nonaflate, —SiMe₂F, —SiMeF₂, —O—SO₂Z¹, —B(OZ²)₂,—CZ³═C(Z³)₂, —C≡CH, —C≡CSi(Z¹)₃, —ZnX⁰ and —Sn(Z⁴)₃, wherein X⁰ ishalogen, Z¹⁻⁴ are selected from the group consisting of alkyl and aryl,each being optionally substituted, and two groups Z² may also form acycloboronate group having 2 to 20 C atoms together with the B- andO-atoms, with each other or with one or monomers of the followingformulae in an aryl aryl coupling reactionR²³-Sp-R²⁴  MIR²³-A-R²⁴  MIIR²³-D-R²⁴  MIIIR²³-Sp-A-R²⁴  MIVR²³-Sp-D-R²⁴  MVR²³-Sp-A-Sp-R²⁴  MVIR²³-Sp-D-Sp-R²⁴  MVII wherein D denotes a donor unit, A denotes anacceptor unit and Sp denotes a spacer unit, all of which are,independently of each other and on each occurrence identically ordifferently, from arylene or heteroarylene that has from 5 to 20 ringatoms, is mono- or polycyclic, optionally contains fused rings, are isunsubstituted or substituted by one or more identical or differentgroups L, and Ar²³⁻²⁴ are, each independently, arylene or heteroarylenethat has 5 to 20 ring atoms, is mono- or polycyclic, optionally containsfused rings, and is unsubstituted or substituted by one or moreidentical or different groups R¹, or CY¹═CY²— or —C≡C—, R¹ is H, F, Cl,CN, or straight-chain, branched or cyclic alkyl with 1 to 30, preferably1 to 20, C atoms, in which one or more CH₂ groups are optionallyreplaced by —O—, —S—, —C(═O)—, —C(═S)—, —C(═O)—O—, —O—C(═O)—, —NR⁰—,—SiR⁰R⁰⁰—, —CF₂—, —CR⁰═CR⁰⁰—, —CY¹═CY²— or —C≡C— in such a manner that Oand/or S atoms are not linked directly to one another, and in which oneor more H atoms are optionally replaced by F, Cl, Br, I or CN, and inwhich one or more CH₂ or CH₃ groups are optionally replaced by acationic or anionic group, or aryl, heteroaryl, arylalkyl,heteroarylalkyl, aryloxy or heteroaryloxy, wherein each of theaforementioned cyclic groups has 5 to 20 ring atoms, is mono- orpolycyclic, does optionally contain fused rings, and is unsubstituted orsubstituted by one or more identical or different groups L, L is F, Cl,—CN, —NC, —NCO, —NCS, —OCN, —SCN, —R⁰, —OR⁰, —SR⁰, —C(═O)X⁰, —C(═O)R⁰,—C(═O)—OR⁰, —O—C(═O)—R⁰, —NH₂, —NHR⁰, —NR⁰R⁰⁰, —C(═O)NHR⁰, —C(═O)NR⁰R⁰⁰,—SO₃R⁰, —SO₂R⁰, —OH, —NO₂, —CF₃, —SF₅, or optionally substituted silyl,or carbyl or hydrocarbyl with 1 to 30 C atoms that is optionallysubstituted and optionally comprises one or more hetero atoms, whereinX⁰ is halogen, Y¹, Y² are, each independently, H, F, Cl or CN, R⁰, R⁰⁰are, each independently, H or linear or branched alkyl with 1 to 20,preferably 1 to 12, C atoms that is optionally fluorinated.
 21. Acomposition comprising one or more compounds according to claim 1, andfurther comprising one or more compounds having one or more of asemiconducting, hole or electron transport, hole or electron blocking,insulating, binding, electrically conducting, photoconducting,photoactive or light emitting property.
 22. A composition comprising acompound according to claim 1, which is an electron acceptor or n-typesemiconductor, and further comprising one or more electron donors orp-type semiconductors selected from conjugated polymers.
 23. Acomposition comprising a compound according to claim 1 which is anelectron donor or p-type semiconductor, and further comprising one ormore electron acceptors or n-type semiconductors, selected fromfullerenes or substituted fullerenes, or from non-fullerene acceptors.24. A semiconducting, charge transporting, electrically conducting,photoconducting, photoactive or light emitting material, comprising acompound according to claim
 1. 25. A formulation comprising one or morecompounds according to claim 1, and further comprising one or moresolvents selected from organic solvents.
 26. An electronic oroptoelectronic device, or a component thereof, or an assembly comprisingit, which comprises a compound according to claim
 1. 27. The electronicor optoelectronic device of claim 26, which is selected from organicfield effect transistors (OFET), organic thin film transistors (OTFT),organic light emitting diodes (OLED), organic light emitting transistors(OLET), organic light emitting electrochemical cell (OLEC), organicphotovoltaic devices (OPV), organic photodetectors (OPD), organic solarcells, dye-sensitized solar cells (DSSC), organic photoelectrochemicalcells (OPEC), perovskite-based solar cells (PSC), laser diodes, Schottkydiodes, photoconductors, photodetectors and thermoelectric devices. 28.The component of claim 26, which is selected from charge injectionlayers, charge transport layers, interlayers, planarising layers,antistatic films, polymer electrolyte membranes (PEM), conductingsubstrates and conducting patterns.
 29. The assembly of claim 26, whichis selected from integrated circuits (IC), radio frequencyidentification (RFID) tags, security markings, security devices, flatpanel displays, backlights of flat panel displays, electrophotographicdevices, electrophotographic recording devices, organic memory devices,sensor devices, biosensors and biochips.
 30. A bulk heterojunction (BHJ)formed from a composition according to claim 22.